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# Lucky and even lucky numbers

Lucky and even lucky numbers
You are encouraged to solve this task according to the task description, using any language you may know.

Note that in the following explanation list indices are assumed to start at one.

Definition of lucky numbers

Lucky numbers are positive integers that are formed by:

1. Form a list of all the positive odd integers > 0
${\displaystyle 1,3,5,7,9,11,13,15,17,19,21,23,25,27,29,31,33,35,37,39...}$
2. Return the first number from the list (which is 1).
3. (Loop begins here)
• Note then return the second number from the list (which is 3).
• Discard every third, (as noted), number from the list to form the new list
${\displaystyle 1,3,7,9,13,15,19,21,25,27,31,33,37,39,43,45,49,51,55,57...}$
4. (Expanding the loop a few more times...)
• Note then return the third number from the list (which is 7).
• Discard every 7th, (as noted), number from the list to form the new list
${\displaystyle 1,3,7,9,13,15,21,25,27,31,33,37,43,45,49,51,55,57,63,67...}$
• Note then return the 4th number from the list (which is 9).
• Discard every 9th, (as noted), number from the list to form the new list
${\displaystyle 1,3,7,9,13,15,21,25,31,33,37,43,45,49,51,55,63,67,69,73...}$
• Take the 5th, i.e. 13. Remove every 13th.
• Take the 6th, i.e. 15. Remove every 15th.
• Take the 7th, i.e. 21. Remove every 21th.
• Take the 8th, i.e. 25. Remove every 25th.
5. (Rule for the loop)
• Note the ${\displaystyle n}$th, which is ${\displaystyle m}$.
• Remove every ${\displaystyle m}$th.
• Increment ${\displaystyle n}$.
Definition of even lucky numbers

This follows the same rules as the definition of lucky numbers above except for the very first step:

1. Form a list of all the positive even integers > 0
${\displaystyle 2,4,6,8,10,12,14,16,18,20,22,24,26,28,30,32,34,36,38,40...}$
2. Return the first number from the list (which is 2).
3. (Loop begins here)
• Note then return the second number from the list (which is 4).
• Discard every 4th, (as noted), number from the list to form the new list
${\displaystyle 2,4,6,10,12,14,18,20,22,26,28,30,34,36,38,42,44,46,50,52...}$
4. (Expanding the loop a few more times...)
• Note then return the third number from the list (which is 6).
• Discard every 6th, (as noted), number from the list to form the new list
${\displaystyle 2,4,6,10,12,18,20,22,26,28,34,36,38,42,44,50,52,54,58,60...}$
• Take the 4th, i.e. 10. Remove every 10th.
• Take the 5th, i.e. 12. Remove every 12th.
5. (Rule for the loop)
• Note the ${\displaystyle n}$th, which is ${\displaystyle m}$.
• Remove every ${\displaystyle m}$th.
• Increment ${\displaystyle n}$.
• Write one or two subroutines (functions) to generate lucky numbers and even lucky numbers
• Write a command-line interface to allow selection of which kind of numbers and which number(s). Since input is from the command line, tests should be made for the common errors:
• missing arguments
• too many arguments
• number (or numbers) aren't legal
• misspelled argument (lucky or evenLucky)
• The command line handling should:
• support mixed case handling of the (non-numeric) arguments
• support printing a particular number
• support printing a range of numbers by their index
• support printing a range of numbers by their values
• The resulting list of numbers should be printed on a single line.

The program should support the arguments:

```                             what is displayed  (on a single line)
argument(s)              (optional verbiage is encouraged)
╔═══════════════════╦════════════════════════════════════════════════════╗
║  j                ║  Jth       lucky number                            ║
║  j  ,      lucky  ║  Jth       lucky number                            ║
║  j  ,  evenLucky  ║  Jth  even lucky number                            ║
║                   ║                                                    ║
║  j  k             ║  Jth  through  Kth (inclusive)       lucky numbers ║
║  j  k      lucky  ║  Jth  through  Kth (inclusive)       lucky numbers ║
║  j  k  evenLucky  ║  Jth  through  Kth (inclusive)  even lucky numbers ║
║                   ║                                                    ║
║  j -k             ║  all       lucky numbers in the range  j ──► |k|   ║
║  j -k      lucky  ║  all       lucky numbers in the range  j ──► |k|   ║
║  j -k  evenLucky  ║  all  even lucky numbers in the range  j ──► |k|   ║
╚═══════════════════╩════════════════════════════════════════════════════╝
where    |k|    is the absolute value of   k
```

Demonstrate the program by:

• showing the first twenty lucky numbers
• showing the first twenty even lucky numbers
• showing all lucky numbers between 6,000 and 6,100 (inclusive)
• showing all even lucky numbers in the same range as above
• showing the 10,000th lucky number (extra credit)
• showing the 10,000th even lucky number (extra credit)

## C

Translation of: C++
`#include <stdbool.h>#include <stdio.h>#include <stdlib.h> #define LUCKY_SIZE 60000int luckyOdd[LUCKY_SIZE];int luckyEven[LUCKY_SIZE]; void compactLucky(int luckyArray[]) {    int i, j, k;     for (i = 0; i < LUCKY_SIZE; i++) {        if (luckyArray[i] == 0) {            j = i;            break;        }    }     for (j = i + 1; j < LUCKY_SIZE; j++) {        if (luckyArray[j] > 0) {            luckyArray[i++] = luckyArray[j];        }    }     for (; i < LUCKY_SIZE; i++) {        luckyArray[i] = 0;    }} void initialize() {    int i, j;     // unfiltered    for (i = 0; i < LUCKY_SIZE; i++) {        luckyEven[i] = 2 * i + 2;        luckyOdd[i] = 2 * i + 1;    }     // odd filter    for (i = 1; i < LUCKY_SIZE; i++) {        if (luckyOdd[i] > 0) {            for (j = luckyOdd[i] - 1; j < LUCKY_SIZE; j += luckyOdd[i]) {                luckyOdd[j] = 0;            }            compactLucky(luckyOdd);        }    }     // even filter    for (i = 1; i < LUCKY_SIZE; i++) {        if (luckyEven[i] > 0) {            for (j = luckyEven[i] - 1; j < LUCKY_SIZE; j += luckyEven[i]) {                luckyEven[j] = 0;            }            compactLucky(luckyEven);        }    }} void printBetween(size_t j, size_t k, bool even) {    int i;     if (even) {        if (luckyEven[j] == 0 || luckyEven[k] == 0) {            fprintf(stderr, "At least one argument is too large\n");            exit(EXIT_FAILURE);        }        printf("Lucky even numbers between %d and %d are:", j, k);        for (i = 0; luckyEven[i] != 0; i++) {            if (luckyEven[i] > k) {                break;            }            if (luckyEven[i] > j) {                printf(" %d", luckyEven[i]);            }        }    } else {        if (luckyOdd[j] == 0 || luckyOdd[k] == 0) {            fprintf(stderr, "At least one argument is too large\n");            exit(EXIT_FAILURE);        }        printf("Lucky numbers between %d and %d are:", j, k);        for (i = 0; luckyOdd[i] != 0; i++) {            if (luckyOdd[i] > k) {                break;            }            if (luckyOdd[i] > j) {                printf(" %d", luckyOdd[i]);            }        }    }    printf("\n");} void printRange(size_t j, size_t k, bool even) {    int i;     if (even) {        if (luckyEven[k] == 0) {            fprintf(stderr, "The argument is too large\n");            exit(EXIT_FAILURE);        }        printf("Lucky even numbers %d to %d are:", j, k);        for (i = j - 1; i < k; i++) {            printf(" %d", luckyEven[i]);        }    } else {        if (luckyOdd[k] == 0) {            fprintf(stderr, "The argument is too large\n");            exit(EXIT_FAILURE);        }        printf("Lucky numbers %d to %d are:", j, k);        for (i = j - 1; i < k; i++) {            printf(" %d", luckyOdd[i]);        }    }    printf("\n");} void printSingle(size_t j, bool even) {    if (even) {        if (luckyEven[j] == 0) {            fprintf(stderr, "The argument is too large\n");            exit(EXIT_FAILURE);        }        printf("Lucky even number %d=%d\n", j, luckyEven[j - 1]);    } else {        if (luckyOdd[j] == 0) {            fprintf(stderr, "The argument is too large\n");            exit(EXIT_FAILURE);        }        printf("Lucky number %d=%d\n", j, luckyOdd[j - 1]);    }} void help() {    printf("./lucky j [k] [--lucky|--evenLucky]\n");    printf("\n");    printf("       argument(s)        |  what is displayed\n");    printf("==============================================\n");    printf("-j=m                      |  mth lucky number\n");    printf("-j=m  --lucky             |  mth lucky number\n");    printf("-j=m  --evenLucky         |  mth even lucky number\n");    printf("-j=m  -k=n                |  mth through nth (inclusive) lucky numbers\n");    printf("-j=m  -k=n  --lucky       |  mth through nth (inclusive) lucky numbers\n");    printf("-j=m  -k=n  --evenLucky   |  mth through nth (inclusive) even lucky numbers\n");    printf("-j=m  -k=-n               |  all lucky numbers in the range [m, n]\n");    printf("-j=m  -k=-n  --lucky      |  all lucky numbers in the range [m, n]\n");    printf("-j=m  -k=-n  --evenLucky  |  all even lucky numbers in the range [m, n]\n");} void process(int argc, char *argv[]) {    bool evenLucky = false;    int j = 0;    int k = 0;     bool good = false;    int i;     for (i = 1; i < argc; ++i) {        if ('-' == argv[i][0]) {            if ('-' == argv[i][1]) {                // long args                if (0 == strcmp("--lucky", argv[i])) {                    evenLucky = false;                } else if (0 == strcmp("--evenLucky", argv[i])) {                    evenLucky = true;                } else {                    fprintf(stderr, "Unknown long argument: [%s]\n", argv[i]);                    exit(EXIT_FAILURE);                }            } else {                // short args                if ('j' == argv[i][1] && '=' == argv[i][2] && argv[i][3] != 0) {                    good = true;                    j = atoi(&argv[i][3]);                } else if ('k' == argv[i][1] && '=' == argv[i][2]) {                    k = atoi(&argv[i][3]);                } else {                    fprintf(stderr, "Unknown short argument: [%s]\n", argv[i]);                    exit(EXIT_FAILURE);                }            }        } else {            fprintf(stderr, "Unknown argument: [%s]\n", argv[i]);            exit(EXIT_FAILURE);        }    }     if (!good) {        help();        exit(EXIT_FAILURE);    }     if (k > 0) {        printRange(j, k, evenLucky);    } else if (k < 0) {        printBetween(j, -k, evenLucky);    } else {        printSingle(j, evenLucky);    }} void test() {    printRange(1, 20, false);    printRange(1, 20, true);     printBetween(6000, 6100, false);    printBetween(6000, 6100, true);     printSingle(10000, false);    printSingle(10000, true);} int main(int argc, char *argv[]) {    initialize();     //test();     if (argc < 2) {        help();        return 1;    }    process(argc, argv);     return 0;}`
Output:
```LuckyNumbers.exe -j=1 -k=20
Lucky numbers 1 to 20 are: 1 3 7 9 13 15 21 25 31 33 37 43 49 51 63 67 69 73 75 79

LuckyNumbers.exe -j=1 -k=20 --evenLucky
Lucky even numbers 1 to 20 are: 2 4 6 10 12 18 20 22 26 34 36 42 44 50 52 54 58 68 70 76

LuckyNumbers.exe -j=6000 -k=-6100
Lucky numbers between 6000 and 6100 are: 6009 6019 6031 6049 6055 6061 6079 6093

LuckyNumbers.exe -j=6000 -k=-6100 --evenLucky
Lucky even numbers between 6000 and 6100 are: 6018 6020 6022 6026 6036 6038 6050 6058 6074 6090 6092

LuckyNumbers.exe -j=10000
Lucky number 10000=115591

LuckyNumbers.exe -j=10000 --evenLucky
Lucky even number 10000=111842```

## C++

Translation of: Go
`#include <algorithm>#include <iostream>#include <iterator>#include <vector> const int luckySize = 60000;std::vector<int> luckyEven(luckySize);std::vector<int> luckyOdd(luckySize); void init() {    for (int i = 0; i < luckySize; ++i) {        luckyEven[i] = i * 2 + 2;        luckyOdd[i] = i * 2 + 1;    }} void filterLuckyEven() {    for (size_t n = 2; n < luckyEven.size(); ++n) {        int m = luckyEven[n - 1];        int end = (luckyEven.size() / m) * m - 1;        for (int j = end; j >= m - 1; j -= m) {            std::copy(luckyEven.begin() + j + 1, luckyEven.end(), luckyEven.begin() + j);            luckyEven.pop_back();        }    }} void filterLuckyOdd() {    for (size_t n = 2; n < luckyOdd.size(); ++n) {        int m = luckyOdd[n - 1];        int end = (luckyOdd.size() / m) * m - 1;        for (int j = end; j >= m - 1; j -= m) {            std::copy(luckyOdd.begin() + j + 1, luckyOdd.end(), luckyOdd.begin() + j);            luckyOdd.pop_back();        }    }} void printBetween(size_t j, size_t k, bool even) {    std::ostream_iterator<int> out_it{ std::cout, ", " };     if (even) {        size_t max = luckyEven.back();        if (j > max || k > max) {            std::cerr << "At least one are is too big\n";            exit(EXIT_FAILURE);        }         std::cout << "Lucky even numbers between " << j << " and " << k << " are: ";        std::copy_if(luckyEven.begin(), luckyEven.end(), out_it, [j, k](size_t n) {            return j <= n && n <= k;        });    } else {        size_t max = luckyOdd.back();        if (j > max || k > max) {            std::cerr << "At least one are is too big\n";            exit(EXIT_FAILURE);        }         std::cout << "Lucky numbers between " << j << " and " << k << " are: ";        std::copy_if(luckyOdd.begin(), luckyOdd.end(), out_it, [j, k](size_t n) {            return j <= n && n <= k;        });    }    std::cout << '\n';} void printRange(size_t j, size_t k, bool even) {    std::ostream_iterator<int> out_it{ std::cout, ", " };    if (even) {        if (k >= luckyEven.size()) {            std::cerr << "The argument is too large\n";            exit(EXIT_FAILURE);        }        std::cout << "Lucky even numbers " << j << " to " << k << " are: ";        std::copy(luckyEven.begin() + j - 1, luckyEven.begin() + k, out_it);    } else {        if (k >= luckyOdd.size()) {            std::cerr << "The argument is too large\n";            exit(EXIT_FAILURE);        }        std::cout << "Lucky numbers " << j << " to " << k << " are: ";        std::copy(luckyOdd.begin() + j - 1, luckyOdd.begin() + k, out_it);    }} void printSingle(size_t j, bool even) {    if (even) {        if (j >= luckyEven.size()) {            std::cerr << "The argument is too large\n";            exit(EXIT_FAILURE);        }        std::cout << "Lucky even number " << j << "=" << luckyEven[j - 1] << '\n';    } else {        if (j >= luckyOdd.size()) {            std::cerr << "The argument is too large\n";            exit(EXIT_FAILURE);        }        std::cout << "Lucky number " << j << "=" << luckyOdd[j - 1] << '\n';    }} void help() {    std::cout << "./lucky j [k] [--lucky|--evenLucky]\n";    std::cout << "\n";    std::cout << "       argument(s)        |  what is displayed\n";    std::cout << "==============================================\n";    std::cout << "-j=m                      |  mth lucky number\n";    std::cout << "-j=m  --lucky             |  mth lucky number\n";    std::cout << "-j=m  --evenLucky         |  mth even lucky number\n";    std::cout << "-j=m  -k=n                |  mth through nth (inclusive) lucky numbers\n";    std::cout << "-j=m  -k=n  --lucky       |  mth through nth (inclusive) lucky numbers\n";    std::cout << "-j=m  -k=n  --evenLucky   |  mth through nth (inclusive) even lucky numbers\n";    std::cout << "-j=m  -k=-n               |  all lucky numbers in the range [m, n]\n";    std::cout << "-j=m  -k=-n  --lucky      |  all lucky numbers in the range [m, n]\n";    std::cout << "-j=m  -k=-n  --evenLucky  |  all even lucky numbers in the range [m, n]\n";} int main(int argc, char **argv) {    bool evenLucky = false;    int j = 0;    int k = 0;     // skip arg 0, because that is just the executable name    if (argc < 2) {        help();        exit(EXIT_FAILURE);    }     bool good = false;    for (int i = 1; i < argc; ++i) {        if ('-' == argv[i][0]) {            if ('-' == argv[i][1]) {                // long args                if (0 == strcmp("--lucky", argv[i])) {                    evenLucky = false;                } else if (0 == strcmp("--evenLucky", argv[i])) {                    evenLucky = true;                } else {                    std::cerr << "Unknown long argument: [" << argv[i] << "]\n";                    exit(EXIT_FAILURE);                }            } else {                // short args                if ('j' == argv[i][1] && '=' == argv[i][2] && argv[i][3] != 0) {                    good = true;                    j = atoi(&argv[i][3]);                } else if ('k' == argv[i][1] && '=' == argv[i][2]) {                    k = atoi(&argv[i][3]);                } else {                    std::cerr << "Unknown short argument: " << argv[i] << '\n';                    exit(EXIT_FAILURE);                }            }        } else {            std::cerr << "Unknown argument: " << argv[i] << '\n';            exit(EXIT_FAILURE);        }    }    if (!good) {        help();        exit(EXIT_FAILURE);    }     init();    filterLuckyEven();    filterLuckyOdd();    if (k > 0) {        printRange(j, k, evenLucky);    } else if (k < 0) {        printBetween(j, -k, evenLucky);    } else {        printSingle(j, evenLucky);    }     return 0;}`
Output:
```>LuckyNumbers.exe -j=1 -k=20
Lucky numbers 1 to 20 are: 1, 3, 7, 9, 13, 15, 21, 25, 31, 33, 37, 43, 49, 51, 63, 67, 69, 73, 75, 79,

>LuckyNumbers.exe -j=1 -k=20 --evenLucky
Lucky even numbers 1 to 20 are: 2, 4, 6, 10, 12, 18, 20, 22, 26, 34, 36, 42, 44, 50, 52, 54, 58, 68, 70, 76,

>LuckyNumbers.exe -j=6000 -k=-6100
Lucky numbers between 6000 and 6100 are: 6009, 6019, 6031, 6049, 6055, 6061, 6079, 6093,

>LuckyNumbers.exe -j=6000 -k=-6100 --evenLucky
Lucky even numbers between 6000 and 6100 are: 6018, 6020, 6022, 6026, 6036, 6038, 6050, 6058, 6074, 6090, 6092,

>LuckyNumbers.exe -j=10000
Lucky number 10000=115591

>LuckyNumbers.exe -j=10000 --evenLucky
Lucky even number 10000=111842```

## D

`import std.algorithm;import std.concurrency;import std.conv;import std.getopt;import std.range;import std.stdio; auto lucky(bool even, int nmax=200_000) {    import std.container.array;     int start = even ? 2 : 1;     return new Generator!int({        auto ln = make!(Array!int)(iota(start,nmax,2));         // yield the first number        yield(ln[0]);         int n=1;        for(; n<ln.length/2+1; n++) {            yield(ln[n]);             int step = ln[n]-1;             // remove the non-lucky numbers related to the current lucky number            for (int i=step; i<ln.length; i+=step) {                ln.linearRemove(ln[].drop(i).take(1));            }        }         // yield all remaining values        foreach(val; ln[n..\$]) {            yield(val);        }    });} void help(Option[] opt) {    defaultGetoptPrinter("./lucky j [k] [--lucky|--evenLucky]", opt);     writeln;    writeln("       argument(s)        |  what is displayed");    writeln("==============================================");    writeln("-j=m                      |  mth lucky number");    writeln("-j=m  --lucky             |  mth lucky number");    writeln("-j=m  --evenLucky         |  mth even lucky number");    writeln("-j=m  -k=n                |  mth through nth (inclusive) lucky numbers");    writeln("-j=m  -k=n  --lucky       |  mth through nth (inclusive) lucky numbers");    writeln("-j=m  -k=n  --evenLucky   |  mth through nth (inclusive) even lucky numbers");    writeln("-j=m  -k=-n               |  all lucky numbers in the range [m, n]");    writeln("-j=m  -k=-n  --lucky      |  all lucky numbers in the range [m, n]");    writeln("-j=m  -k=-n  --evenLucky  |  all even lucky numbers in the range [m, n]");} void main(string[] args) {    int j;    int k;    bool evenLucky = false;     void luckyOpt() {        evenLucky = false;    }    auto helpInformation = getopt(        args,        std.getopt.config.passThrough,        std.getopt.config.required,        "j", "The starting point to generate lucky numbers", &j,        "k", "The ending point for generating lucky numbers", &k,        "lucky", "Specify to generate a list of lucky numbers", &luckyOpt,        "evenLucky", "Specify to generate a list of even lucky numbers", &evenLucky    );     if (helpInformation.helpWanted) {        help(helpInformation.options);        return;    }     if (k>0) {        lucky(evenLucky).drop(j-1).take(k-j+1).writeln;    } else if (k<0) {        auto f = (int a) => j<=a && a<=-k;        lucky(evenLucky, -k).filter!f.writeln;    } else {        lucky(evenLucky).drop(j-1).take(1).writeln;    }}`
Output:
```.\lucky_and_even_lucky_numbers.exe -j=1 -k=20
[1, 3, 7, 9, 13, 15, 21, 25, 31, 33, 37, 43, 49, 51, 63, 67, 69, 73, 75, 79]

.\lucky_and_even_lucky_numbers.exe -j=1 -k=20 --evenLucky
[2, 4, 6, 10, 12, 18, 20, 22, 26, 34, 36, 42, 44, 50, 52, 54, 58, 68, 70, 76]

.\lucky_and_even_lucky_numbers.exe -j=6000 -k=-6100
[6009, 6019, 6031, 6049, 6055, 6061, 6079, 6093]

.\lucky_and_even_lucky_numbers.exe -j=6000 -k=-6100 --evenLucky
[6018, 6020, 6022, 6026, 6036, 6038, 6050, 6058, 6074, 6090, 6092]

.\lucky_and_even_lucky_numbers.exe -j=10000
[115591]

.\lucky_and_even_lucky_numbers.exe -j=10000 --evenLucky
[111842]```

## F#

### The functions

` // Odd and Even Lucky Numbers. Nigel Galloway: October 3rd., 2020let rec fN i g e l=seq{yield! i|>Seq.skip g|>Seq.take(e-g-1)                       let n=Seq.chunkBySize e i|>Seq.collect(Seq.take(e-1)) in yield! fN n (e-1) (Seq.item l n) (l+1)}let oLuck,eLuck=let rec fG g=seq{yield g; yield! fG(g+2)} in (fN(fG 1) 0 3 2,fN(fG 2) 0 4 2) `

Using a fsi console:

Output:
```> oLuck|>Seq.take 20|>Seq.iter(printf "%d "); printfn "";;
1 3 7 9 13 15 21 25 31 33 37 43 49 51 63 67 69 73 75 79

> eLuck|>Seq.take 20|>Seq.iter(printf "%d "); printfn "";;
2 4 6 10 12 18 20 22 26 34 36 42 44 50 52 54 58 68 70 76

> oLuck|>Seq.skipWhile(fun n->n<6000)|>Seq.takeWhile(fun n->n<6100)|>Seq.iter(printf "%d "); printfn "";;
6009 6019 6031 6049 6055 6061 6079 6093

> eLuck|>Seq.skipWhile(fun n->n<6000)|>Seq.takeWhile(fun n->n<6100)|>Seq.iter(printf "%d "); printfn "";;
6018 6020 6022 6026 6036 6038 6050 6058 6074 6090 6092
```

## Go

Translation of: Kotlin
`package main import (    "fmt"    "log"    "os"    "strconv"    "strings") const luckySize = 60000 var luckyOdd = make([]int, luckySize)var luckyEven = make([]int, luckySize) func init() {    for i := 0; i < luckySize; i++ {        luckyOdd[i] = i*2 + 1        luckyEven[i] = i*2 + 2    }} func filterLuckyOdd() {    for n := 2; n < len(luckyOdd); n++ {        m := luckyOdd[n-1]        end := (len(luckyOdd)/m)*m - 1        for j := end; j >= m-1; j -= m {            copy(luckyOdd[j:], luckyOdd[j+1:])            luckyOdd = luckyOdd[:len(luckyOdd)-1]        }    }} func filterLuckyEven() {    for n := 2; n < len(luckyEven); n++ {        m := luckyEven[n-1]        end := (len(luckyEven)/m)*m - 1        for j := end; j >= m-1; j -= m {            copy(luckyEven[j:], luckyEven[j+1:])            luckyEven = luckyEven[:len(luckyEven)-1]        }    }} func printSingle(j int, odd bool) error {    if odd {        if j >= len(luckyOdd) {            return fmt.Errorf("the argument, %d, is too big", j)        }        fmt.Println("Lucky number", j, "=", luckyOdd[j-1])    } else {        if j >= len(luckyEven) {            return fmt.Errorf("the argument, %d, is too big", j)        }        fmt.Println("Lucky even number", j, "=", luckyEven[j-1])    }    return nil} func printRange(j, k int, odd bool) error {    if odd {        if k >= len(luckyOdd) {            return fmt.Errorf("the argument, %d, is too big", k)        }        fmt.Println("Lucky numbers", j, "to", k, "are:")        fmt.Println(luckyOdd[j-1 : k])    } else {        if k >= len(luckyEven) {            return fmt.Errorf("the argument, %d, is too big", k)        }        fmt.Println("Lucky even numbers", j, "to", k, "are:")        fmt.Println(luckyEven[j-1 : k])    }    return nil} func printBetween(j, k int, odd bool) error {    var r []int    if odd {        max := luckyOdd[len(luckyOdd)-1]        if j > max || k > max {            return fmt.Errorf("at least one argument, %d or %d, is too big", j, k)        }        for _, num := range luckyOdd {            if num < j {                continue            }            if num > k {                break            }            r = append(r, num)        }        fmt.Println("Lucky numbers between", j, "and", k, "are:")        fmt.Println(r)    } else {        max := luckyEven[len(luckyEven)-1]        if j > max || k > max {            return fmt.Errorf("at least one argument, %d or %d, is too big", j, k)        }        for _, num := range luckyEven {            if num < j {                continue            }            if num > k {                break            }            r = append(r, num)        }        fmt.Println("Lucky even numbers between", j, "and", k, "are:")        fmt.Println(r)    }    return nil} func main() {    nargs := len(os.Args)    if nargs < 2 || nargs > 4 {        log.Fatal("there must be between 1 and 3 command line arguments")    }    filterLuckyOdd()    filterLuckyEven()    j, err := strconv.Atoi(os.Args[1])    if err != nil || j < 1 {        log.Fatalf("first argument, %s, must be a positive integer", os.Args[1])    }    if nargs == 2 {        if err := printSingle(j, true); err != nil {            log.Fatal(err)        }        return    }     if nargs == 3 {        k, err := strconv.Atoi(os.Args[2])        if err != nil {            log.Fatalf("second argument, %s, must be an integer", os.Args[2])        }        if k >= 0 {            if j > k {                log.Fatalf("second argument, %d, can't be less than first, %d", k, j)            }            if err := printRange(j, k, true); err != nil {                log.Fatal(err)            }        } else {            l := -k            if j > l {                log.Fatalf("second argument, %d, can't be less in absolute value than first, %d", k, j)            }            if err := printBetween(j, l, true); err != nil {                log.Fatal(err)            }        }        return    }     var odd bool    switch lucky := strings.ToLower(os.Args[3]); lucky {    case "lucky":        odd = true    case "evenlucky":        odd = false    default:        log.Fatalf("third argument, %s, is invalid", os.Args[3])    }    if os.Args[2] == "," {        if err := printSingle(j, odd); err != nil {            log.Fatal(err)        }        return    }     k, err := strconv.Atoi(os.Args[2])    if err != nil {        log.Fatal("second argument must be an integer or a comma")    }    if k >= 0 {        if j > k {            log.Fatalf("second argument, %d, can't be less than first, %d", k, j)        }        if err := printRange(j, k, odd); err != nil {            log.Fatal(err)        }    } else {        l := -k        if j > l {            log.Fatalf("second argument, %d, can't be less in absolute value than first, %d", k, j)        }        if err := printBetween(j, l, odd); err != nil {            log.Fatal(err)        }    }}`
Output:
```\$ ./lucky 1 20
Lucky numbers 1 to 20 are:
[1 3 7 9 13 15 21 25 31 33 37 43 49 51 63 67 69 73 75 79]

\$ ./lucky 1 20 evenLucky
Lucky even numbers 1 to 20 are:
[2 4 6 10 12 18 20 22 26 34 36 42 44 50 52 54 58 68 70 76]

\$ ./lucky 6000 -6100
Lucky numbers between 6000 and 6100 are:
[6009 6019 6031 6049 6055 6061 6079 6093]

\$ ./lucky 6000 -6100 evenLucky
Lucky even numbers between 6000 and 6100 are:
[6018 6020 6022 6026 6036 6038 6050 6058 6074 6090 6092]

\$ ./lucky 10000 , lucky
Lucky number 10000 = 115591

\$ ./lucky 10000 , evenLucky
Lucky even number 10000 = 111842
```

Haskell is a very nice language for this problem because it is a lazy language. Here regular expressions and data types are used.

` import System.Environmentimport Text.Regex.Posix data Lucky = Lucky | EvenLucky  helpMessage :: IO ()helpMessage = do  putStrLn "                           what is displayed  (on a single line)"  putStrLn "     argument(s)              (optional verbiage is encouraged)"  putStrLn "======================|==================================================="  putStrLn " j                    | Jth       lucky number                            "  putStrLn " j  ,          lucky  | Jth       lucky number                            "  putStrLn " j  ,      evenLucky  | Jth  even lucky number                            "  putStrLn "                                                                          "  putStrLn " j  k                 | Jth  through  Kth (inclusive)       lucky numbers "  putStrLn " j  k          lucky  | Jth  through  Kth (inclusive)       lucky numbers "  putStrLn " j  k      evenlucky  | Jth  through  Kth (inclusive)  even lucky numbers "  putStrLn "                                                                          "  putStrLn " j -k                 | all       lucky numbers in the range  j -> |k|    "  putStrLn " j -k          lucky  | all       lucky numbers in the range  j -> |k|    "  putStrLn " j -k      evenlucky  | all  even lucky numbers in the range  j -> |k|    "  putStrLn "======================|===================================================" oddNumbers :: [Int]oddNumbers = filter odd [1..] evenNumbers :: [Int]evenNumbers = filter even [1..] luckyNumbers :: [Int] -> [Int]luckyNumbers xs =   let i = 3 in  sieve i xs    where      sieve i (ln:s:xs) =        ln : sieve (i + 1) (s : [x | (n, x) <- zip [i..] xs, rem n s /= 0]) nth :: Int -> Lucky -> Intnth j Lucky     = luckyNumbers oddNumbers !! (j-1)nth j EvenLucky = luckyNumbers evenNumbers !! (j-1) range :: Int -> Int -> Lucky -> [Int]range x x2 Lucky     = drop (x-1) (take x2 (luckyNumbers oddNumbers))range x x2 EvenLucky = drop (x-1) (take x2 (luckyNumbers evenNumbers)) interval :: Int -> Int -> Lucky -> [Int]interval x x2 Lucky     = dropWhile (<x) (takeWhile (<=x2) (luckyNumbers oddNumbers))interval x x2 EvenLucky = dropWhile (<x) (takeWhile (<=x2) (luckyNumbers evenNumbers)) lucky :: [String] -> Luckylucky xs =   if "evenLucky" `elem` xs   then EvenLucky   else Lucky readn :: String -> Intreadn s = read s :: Int isInt :: String -> BoolisInt s = not (null (s =~ "-?[0-9]{0,10}" :: String)) main :: IO ()main = do  args <- getArgs  if head args == "--help" || null args    then      helpMessage    else      let l = lucky args in      case map readn (filter isInt args) of        [] -> do          putStrLn "Invalid input, missing arguments"          putStrLn "Type --help"        [x] -> print (nth x l)        [x, x2] -> if x2 > 0          then print (range x x2 l)          else print (interval x (-x2) l)        _ -> do           putStrLn "Invalid input, wrong number of arguments"          putStrLn "Type --help"`
Output:
```\$ luckyNumbers 1 20
[1,3,7,9,13,15,21,25,31,33,37,43,49,51,63,67,69,73,75,79]
\$ luckyNumbers 1 20 evenLucky
[2,4,6,10,12,18,20,22,26,34,36,42,44,50,52,54,58,68,70,76]
\$ luckyNumbers 6000 -6100 lucky
[6009,6019,6031,6049,6055,6061,6079,6093]
\$ luckyNumbers 6000 -6100 evenLucky
[6018,6020,6022,6026,6036,6038,6050,6058,6074,6090,6092]
\$ luckyNumbers 10000
115591
\$ luckyNumbers 10000 evenLucky
111842```

## J

Not going for extra credit because I want to encourage functional reactive "types" in J. (Note that FRP, along with an ML typed compiler, would probably remove the motivation for the while loop in this implementation.)

Implementation:

`luckySeq=:3 :0  1 luckySeq y:  len=.0  nth=.0  seq=.x+2*i.4*y  while.  len~:#seq do.    len=. #seq    nth=. nth+1    seq=. nth exclude seq  end.) exclude=: ] #~ 1 - #@] \$ [email protected]{ {. 1: lucky=:''evenLucky=:0program=:3 :0  range=: |y-.0  seq=. (1+0 e.y) luckySeq >./range  if. 0><./y do.    (#~ e.&(thru/range)) seq  else.    (<:thru/range) { seq  end.) thru=: <./ + [email protected](+*)@-~`

`   program 1 201 3 7 9 13 15 21 25 31 33 37 43 49 51 63 67 69 73 75 79   program 1 20,evenLucky2 4 6 10 12 18 20 22 26 34 36 42 44 50 52 54 58 68 70 76   program 6000,-61006009 6019 6031 6049 6055 6061 6079 6093   program 6000,-6100,evenLucky6018 6020 6022 6026 6036 6038 6050 6058 6074 6090 6092`

Note that I've used the J command line rather than a unix or windows command line. This is because J is portable to a wide variety of environments (including phones) and there's no reliably common command line that exists across all these environments. Therefore, J must provide its own, and J's command line requires some slight syntax changes from the suggestions implicit in this task.

## Java

` import java.util.ArrayList;import java.util.Collections;import java.util.List; public class LuckyNumbers {     private static int MAX = 200000;    private static List<Integer> luckyEven = luckyNumbers(MAX, true);    private static List<Integer> luckyOdd = luckyNumbers(MAX, false);     public static void main(String[] args) {        //  Case 1 and 2        if ( args.length == 1 || ( args.length == 2 && args[1].compareTo("lucky") == 0 ) ) {            int n = Integer.parseInt(args[0]);            System.out.printf("LuckyNumber(%d) = %d%n", n, luckyOdd.get(n-1));        }        //  Case 3        else if ( args.length == 2 && args[1].compareTo("evenLucky") == 0 ) {            int n = Integer.parseInt(args[0]);            System.out.printf("EvenLuckyNumber(%d) = %d%n", n, luckyEven.get(n-1));                    }        //  Case 4 through 9        else if ( args.length == 2 || args.length == 3 ) {            int j = Integer.parseInt(args[0]);            int k = Integer.parseInt(args[1]);            //  Case 4 and 5            if ( ( args.length == 2 && k > 0 ) || (args.length == 3 && k > 0 && args[2].compareTo("lucky") == 0 ) ) {                System.out.printf("LuckyNumber(%d) through LuckyNumber(%d) = %s%n", j, k, luckyOdd.subList(j-1, k));            }            //  Case 6            else if ( args.length == 3 && k > 0 && args[2].compareTo("evenLucky") == 0 ) {                System.out.printf("EvenLuckyNumber(%d) through EvenLuckyNumber(%d) = %s%n", j, k, luckyEven.subList(j-1, k));            }            //  Case 7 and 8            else if ( ( args.length == 2 && k < 0 ) || (args.length == 3 && k < 0 && args[2].compareTo("lucky") == 0 ) ) {                int n = Collections.binarySearch(luckyOdd, j);                int m = Collections.binarySearch(luckyOdd, -k);                System.out.printf("Lucky Numbers in the range %d to %d inclusive = %s%n", j, -k, luckyOdd.subList(n < 0 ? -n-1 : n, m < 0 ? -m-1 : m+1));            }            //  Case 9            else if ( args.length == 3 && k < 0 && args[2].compareTo("evenLucky") == 0 ) {                int n = Collections.binarySearch(luckyEven, j);                int m = Collections.binarySearch(luckyEven, -k);                System.out.printf("Even Lucky Numbers in the range %d to %d inclusive = %s%n", j, -k, luckyEven.subList(n < 0 ? -n-1 : n, m < 0 ? -m-1 : m+1));            }        }    }     private static List<Integer> luckyNumbers(int max, boolean even) {        List<Integer> luckyList = new ArrayList<>();        for ( int i = even ? 2 : 1 ; i <= max ; i += 2 ) {            luckyList.add(i);        }        int start = 1;        boolean removed = true;        while ( removed ) {            removed = false;            int increment = luckyList.get(start);            List<Integer> remove = new ArrayList<>();            for ( int i = increment-1 ; i < luckyList.size() ; i += increment ) {                remove.add(0, i);                removed = true;            }            for ( int i : remove ) {                luckyList.remove(i);            }            start++;        }        return luckyList;    } } `
Output:
```C:\My_Data\software\EclipseOxygenProjects\Rosetta Code\bin>java LuckyNumbers 1 20
LuckyNumber(1) through LuckyNumber(20) = [1, 3, 7, 9, 13, 15, 21, 25, 31, 33, 37, 43, 49, 51, 63, 67, 69, 73, 75, 79]

C:\My_Data\software\EclipseOxygenProjects\Rosetta Code\bin>java LuckyNumbers 1 20 evenLucky
EvenLuckyNumber(1) through EvenLuckyNumber(20) = [2, 4, 6, 10, 12, 18, 20, 22, 26, 34, 36, 42, 44, 50, 52, 54, 58, 68, 70, 76]

C:\My_Data\software\EclipseOxygenProjects\Rosetta Code\bin>java LuckyNumbers 6000 -6100
Lucky Numbers in the range 6000 to 6100 inclusive = [6009, 6019, 6031, 6049, 6055, 6061, 6079, 6093]

C:\My_Data\software\EclipseOxygenProjects\Rosetta Code\bin>java LuckyNumbers 6000 -6100 evenLucky
Even Lucky Numbers in the range 6000 to 6100 inclusive = [6018, 6020, 6022, 6026, 6036, 6038, 6050, 6058, 6074, 6090, 6092]

C:\My_Data\software\EclipseOxygenProjects\Rosetta Code\bin>java LuckyNumbers 10000
LuckyNumber(10000) = 115591

C:\My_Data\software\EclipseOxygenProjects\Rosetta Code\bin>java LuckyNumbers 10000 evenLucky
EvenLuckyNumber(10000) = 111842
```

## JavaScript

First: the function.

` function luckyNumbers(opts={}) {  /**************************************************************************\  | OPTIONS                                                                  |  |**************************************************************************|  |   even ...... boolean ............. return even/uneven numbers           |  |                                     (default: false)                     |  |                                                                          |  |   nth ....... number ............... return nth number                   |  |                                                                          |  |   through ... number ............... return numbers from #1 to number    |  |               OR array[from, to] ... return numbers on index             |  |                                      from array[from] to array[to]       |  |                                                                          |  |   range ..... array[from, to] ...... return numbers between from and to  |  \**************************************************************************/   opts.even =  opts.even || false;  if (typeof opts.through == 'number') opts.through = [0, opts.through];  let out = [],      x = opts.even ? 2 : 1,      max = opts.range ? opts.range[1] * 3        : opts.through ? opts.through[1] * 12        : opts.nth ? opts.nth * 15        : 2000;   for (x; x <= max; x = x+2) out.push(x);            // fill  for (x = 1; x < Math.floor(out.length / 2); x++) { // sieve    let i = out.length;    while (i--)      (i+1) % out[x] == 0 && out.splice(i, 1);  }   if (opts.nth) return out[opts.nth-1];  if (opts.through) return out.slice(opts.through[0], opts.through[1]);  if (opts.range) return out.filter(function(val) {      return val >= opts.range[0] && val <= opts.range[1];    });  return out;} /* TESTING */// blankconsole.log( luckyNumbers() );// showing the first twenty lucky numbersconsole.log( luckyNumbers({through: 20}) );// showing the first twenty even lucky numbersconsole.log( luckyNumbers({even: true, through: 20}) );// showing all lucky numbers between 6,000 and 6,100 (inclusive)console.log( luckyNumbers({range: [6000, 6100]}) );// showing all even lucky numbers in the same range as aboveconsole.log( luckyNumbers({even: true, range: [6000, 6100]}) );// showing the 10,000th lucky number (extra credit)console.log( luckyNumbers({nth: 10000}) );// showing the 10,000th even lucky number (extra credit)console.log( luckyNumbers({even: true, nth: 10000}) ); `
Output:
```
> Array(276) [ 1, 3, 7, 9, 13, 15, 21, 25, 31, 33, … ]
> Array(20) [ 1, 3, 7, 9, 13, 15, 21, 25, 31, 33, … ]
> Array(20) [ 2, 4, 6, 10, 12, 18, 20, 22, 26, 34, … ]
> Array(8) [ 6009, 6019, 6031, 6049, 6055, 6061, 6079, 6093 ]
> Array(11) [ 6018, 6020, 6022, 6026, 6036, 6038, 6050, 6058, 6074, 6090, … ]
> 115591
> 111842

```

And that's just pretty much it.

But now: our line interpreter!

We'll use an HTML-prompt here, because JavaScript actually doesn't have a command interface on it's own.

` (function() {  document.write(`    <table>      <tr><th>argument(s)<br>space separated</th><th>gives</th></tr>      <tr><td>\$j</td><td><i>j</i><sup>th</sup> lucky number</tr>      <tr><td>\$j lucky</td><td><i>j</i><sup>th</sup> lucky number</tr>      <tr><td>\$j evenLucky</td><td><i>j</i><sup>th</sup> even lucky number</tr>      <tr><td>&nbsp;</td><td>&nbsp;</td></tr>      <tr><td>\$j \$k</td><td><i>J</i><sup>th</sup> through <i>k</i><sup>th</sup> (inclusive) lucky numbers</td></tr>      <tr><td>\$j \$k lucky</td><td><i>J</i><sup>th</sup> through <i>k</i><sup>th</sup> (inclusive) lucky numbers</td></tr>      <tr><td>\$j \$k evenLucky</td><td><i>J</i><sup>th</sup> through <i>k</i><sup>th</sup> (inclusive) even lucky numbers</td></tr>      <tr><td>&nbsp;</td><td>&nbsp;</td></tr>      <tr><td>-\$j</td><td>all lucky numbers in the range 1 .. |<i>j</i>|*</tr>      <tr><td>\$j -\$k</td><td>all lucky numbers in the range <i>j</i> .. |<i>k</i>|*</tr>      <tr><td>\$j -\$k lucky</td><td>all lucky numbers in the range <i>j</i> .. |<i>k</i>|*</tr>      <tr><td>\$j -\$k evenLucky</td><td>all even lucky numbers in the range <i>j</i> .. |<i>k</i>|*</tr>    </table>    <p>* where |<i>x</i>| is the absolute value of <i>x</i></p>  `);  let args = prompt('Enter a luckyNumbers argument string:').split(' '),      numbers = [],      strings = [],      obj = {},      // object to pass to our luckyNumbers function      msg = '';  for (let x = 0; x < args.length; x++) {    if (isNaN(parseInt(args[x]))) strings.push(args[x].toUpperCase());    else numbers.push(parseInt(args[x]));  }  // check strings  switch (true) {    case (strings.length > 1):      msg += 'Too many arguments.';      break;    case (strings.length == 0): break;    case (strings[0] != 'LUCKY' && strings[0] != 'EVENLUCKY'):      msg += `Unknown argument: \${strings[0]}.`;      break;    case (strings[0] == 'EVENLUCKY'): obj.even = true;  }  // check numbers  switch (true) {    case (numbers.length == 0):      msg += 'Missing number argument.';      break;    case (numbers.length > 2):      msg += 'Too many number arguments.';      break;    case (numbers.length == 1):      if (numbers[0] > 0) obj.nth = numbers[0];      else obj.through = Math.abs(numbers[0]);      break;    case (numbers.length == 2):      // both negative      if (numbers[0] < 0 && numbers[1] < 0) {        msg += 'Missing positive argument';        break;      }      // negative + positive      numbers.sort();      if (numbers[0] < 0 && numbers[1] > 0) {        obj.range = [numbers[1], Math.abs(numbers[0])];        break;      }      // both positive      if (numbers[0] > 0 && numbers[1] > 0) {        obj.through = [numbers[0]-1, numbers[1]];      }  }  if (msg.length > 0)    document.write(`<p>\${msg}<br>Reload to try again</p>`);  else {    let res;    try { res = luckyNumbers(obj); }    catch (err) {      document.write(`<p>\${err}<br>Reload to try again</p>`);    }    finally {      if (typeof res == 'object' ) res = res.join(', ');      document.write(`        <p>          <b>Input: </b>\${args.join(' ')}<br>          <b>Result: </b>\${res}        </p>        <p>Reload to continue</p>      `)    }  }})(); `

Using the task demonstrations again, the I/O part looks like:

Output:
```
Input: 1 20
Result: 1, 3, 7, 9, 13, 15, 21, 25, 31, 33, 37, 43, 49, 51, 63, 67, 69, 73, 75, 79
Input: -20 evenLucky
Result: 2, 4, 6, 10, 12, 18, 20, 22, 26, 34, 36, 42, 44, 50, 52, 54, 58, 68, 70, 76
Input: 6000 -6100
Result: 6009, 6019, 6031, 6049, 6055, 6061, 6079, 6093
Input: -6100 evenlucky 6000
Result: 6018, 6020, 6022, 6026, 6036, 6038, 6050, 6058, 6074, 6090, 6092
Input: 10000
Result: 115591
Input: Evenlucky 10000
Result: 111842

```

## Julia

This iterator for lucky numbers is semi-lazy: it completes one pass of the filter each iteration.

`using Base, StringDistances struct Lucky    start::Int    nmax::Int    Lucky(iseven, nmax) = new(iseven ? 2 : 1, nmax)end struct LuckyState    nextindex::Int    sequence::Vector{Int}end Base.eltype(iter::Lucky) = Int function Base.iterate(iter::Lucky, state = LuckyState(1, collect(iter.start:2:iter.nmax)))    if length(state.sequence) < state.nextindex        return nothing    elseif state.nextindex == 1        return (iter.start, LuckyState(2, state.sequence))    end    result = state.sequence[state.nextindex]    newsequence = Vector{Int}()    for (i, el) in enumerate(state.sequence)        if i % result != 0            push!(newsequence, el)        end    end    (result, LuckyState(state.nextindex + 1, newsequence))end function luckyindex(j, wanteven, k=0)    topindex = max(j, k) + 4    luck = Lucky(wanteven, topindex * 20)    iter_result = iterate(luck)    while iter_result != nothing        (elem, state) = iter_result        iter_result = iterate(luck, state)        if iter_result != nothing && iter_result[2].nextindex > topindex            return iter_result[2].sequence[k > j ? (j:k) : j]        end    end    throw("Index \$j out of range for nmax of \$(luck.nmax).")end function luckyrange(j, k, wanteven)    topvalue = max(j, k)    luck = Lucky(wanteven, topvalue + 1)    iter_result = iterate(luck)    (elem, state) = iter_result # save next to last result    while iter_result != nothing        (elem, state) = iter_result        iter_result = iterate(luck, state)    end    filter(x -> (j <= x <= k), state.sequence)end function helpdisplay(exitlevel=1)    println("\n", PROGRAM_FILE, " j [-][k] [lucky|evenLucky]")    println("\tj: index wanted or a starting point (index or value)",             "\n\tk: optional ending point (index), \n\t-k: optional ending point (value)\n")    helpstring =""" | Argument(s)        |    What is printed                                  | |--------------------------------------------------------------------------| | j                  |  jth lucky number (required argument)               | | j , lucky          |  jth lucky number                                   | | j , evenLucky      |  jth even lucky number                              | | j  k               |  jth through kth (inclusive) lucky numbers          | | j  k  lucky        |  jth through kth (inclusive) lucky numbers          | | j  k  evenLucky    |  jth through kth (inclusive) even lucky numbers     | | j  -k              |  all lucky numbers in the value range [m, |k|]      | | j  -k  lucky       |  all lucky numbers in the value range [m, |k|]      | | j  -k  evenLucky   |  all even lucky numbers in the value range [m, |k|] | |--------------------------------------------------------------------------|\n\n"""     println(helpstring)    exit(exitlevel)end function parsecommandline()    comma = false    evenLucky = false    range = false    j = k = 0    if length(ARGS) < 1        helpdisplay()    end    for (pos, arg) in enumerate(ARGS)        if pos == 1            j = tryparse(Int, arg)            if j == nothing                println("The first argument must be a positive integer.\n")                helpdisplay()            end        elseif pos == 2 || (pos == 3 && comma)            k = tryparse(Int, arg)            if k == nothing                k = 0                if arg == ","                    comma = true                    continue                elseif arg == "lucky"                    continue                elseif arg == "evenLucky"                    evenLucky = true                elseif compare(Hamming(), arg, "lucky") > 0.4 || compare(Hamming(), arg, "evenLucky") > 0.4                    println("Did you misspell \"lucky\" or \"evenLucky\"? Check capitalization.\n")                    helpdisplay()                else                    helpdisplay()                end            elseif k < 0                k = -k                range = true            end        elseif pos == 3 || pos == 4 && comma            if arg == ","                comma = true                continue            elseif arg == "lucky"                continue            elseif arg == "evenLucky"                evenLucky = true            elseif compare(Hamming(), arg, "lucky") > 0.1 || compare(Hamming(), arg, "evenLucky") > 0.1                println("Did you misspell "\lucky\" or "\evenLucky\"?\n\n")                helpdisplay()            else                helpdisplay()            end        elseif arg == "lucky"                continue        elseif arg == "evenLucky"                evenLucky = true        else            println("Too many arguments.\n")            helpdisplay()        end    end    (j, k, evenLucky, range)end function runopts()    (j, k, evenLucky, range) = parsecommandline()    if j < 1 || (k != 0 && j >= k)        throw("Lucky number integer parameters out of range: \$(typeof(j)), \$j, \$(typeof(k)), \$k")    end    if range        println(luckyrange(j, k, evenLucky))    else        println(luckyindex(j, evenLucky, k))    endend runopts()`
Output:
```
> julia luckymath.jl 1 20
[1, 3, 7, 9, 13, 15, 21, 25, 31, 33, 37, 43, 49, 51, 63, 67, 69, 73, 75, 79]
> julia luckymath.jl 1 20 evenLucky
[2, 4, 6, 10, 12, 18, 20, 22, 26, 34, 36, 42, 44, 50, 52, 54, 58, 68, 70, 76]
> julia luckymath.jl 6000 -6100
[6009, 6019, 6031, 6049, 6055, 6061, 6079, 6093]
> julia luckymath.jl 6000 -6100 evenLucky
[6018, 6020, 6022, 6026, 6036, 6038, 6050, 6058, 6074, 6090, 6092]
> julia luckymath.jl 10000
115591
> julia luckymath.jl 10000 evenLucky
111842

```

## Kotlin

`// version 1.1.51 typealias IAE = IllegalArgumentException val luckyOdd  = MutableList(100000) { it * 2 + 1 }val luckyEven = MutableList(100000) { it * 2 + 2 } fun filterLuckyOdd() {    var n = 2    while (n < luckyOdd.size) {        val m = luckyOdd[n - 1]        val end = (luckyOdd.size / m) * m - 1        for (j in end downTo m - 1 step m) luckyOdd.removeAt(j)        n++    }} fun filterLuckyEven() {    var n = 2    while (n < luckyEven.size) {        val m = luckyEven[n - 1]        val end = (luckyEven.size / m) * m - 1        for (j in end downTo m - 1 step m) luckyEven.removeAt(j)        n++    }} fun printSingle(j: Int, odd: Boolean) {    if (odd) {        if (j >= luckyOdd.size) throw IAE("Argument is too big")        println("Lucky number \$j = \${luckyOdd[j - 1]}")    }    else {        if (j >= luckyEven.size) throw IAE("Argument is too big")        println("Lucky even number \$j = \${luckyEven[j - 1]}")    }} fun printRange(j: Int, k: Int, odd: Boolean) {    if (odd) {        if (k >= luckyOdd.size) throw IAE("Argument is too big")        println("Lucky numbers \$j to \$k are:\n\${luckyOdd.drop(j - 1).take(k - j + 1)}")    }    else {        if (k >= luckyEven.size) throw IAE("Argument is too big")        println("Lucky even numbers \$j to \$k are:\n\${luckyEven.drop(j - 1).take(k - j + 1)}")    }} fun printBetween(j: Int, k: Int, odd: Boolean) {    val range = mutableListOf<Int>()    if (odd) {        val max = luckyOdd[luckyOdd.lastIndex]        if (j > max || k > max) {            throw IAE("At least one argument is too big")        }        for (num in luckyOdd) {            if (num < j) continue            if (num > k) break            range.add(num)        }        println("Lucky numbers between \$j and \$k are:\n\$range")    }    else {        val max = luckyEven[luckyEven.lastIndex]        if (j > max || k > max) {            throw IAE("At least one argument is too big")        }        for (num in luckyEven) {            if (num < j) continue            if (num > k) break            range.add(num)        }        println("Lucky even numbers between \$j and \$k are:\n\$range")    }} fun main(args: Array<String>) {    if (args.size !in 1..3) throw IAE("There must be between 1 and 3 command line arguments")    filterLuckyOdd()    filterLuckyEven()    val j = args[0].toIntOrNull()    if (j == null || j < 1) throw IAE("First argument must be a positive integer")    if (args.size == 1) { printSingle(j, true); return }     if (args.size == 2) {        val k = args[1].toIntOrNull()        if (k == null) throw IAE("Second argument must be an integer")        if (k >= 0) {            if (j > k) throw IAE("Second argument can't be less than first")            printRange(j, k, true)        }        else {           val l = -k            if (j > l) throw IAE("The second argument can't be less in absolute value than first")            printBetween(j, l, true)        }        return    }     var odd =        if (args[2].toLowerCase() == "lucky") true        else if (args[2].toLowerCase() == "evenlucky") false        else throw IAE("Third argument is invalid")     if (args[1] == ",") {        printSingle(j, odd)        return    }     val k = args[1].toIntOrNull()    if (k == null) throw IAE("Second argument must be an integer or a comma")     if (k >= 0) {        if (j > k) throw IAE("Second argument can't be less than first")        printRange(j, k, odd)    }    else {        val l = -k        if (j > l) throw IAE("The second argument can't be less in absolute value than first")        printBetween(j, l, odd)    }}`
Output:
```\$ java -jar lucky.jar 1 20
Lucky numbers 1 to 20 are:
[1, 3, 7, 9, 13, 15, 21, 25, 31, 33, 37, 43, 49, 51, 63, 67, 69, 73, 75, 79]

\$ java -jar lucky.jar 1 20 evenLucky
Lucky even numbers 1 to 20 are:
[2, 4, 6, 10, 12, 18, 20, 22, 26, 34, 36, 42, 44, 50, 52, 54, 58, 68, 70, 76]

\$ java -jar lucky.jar 6000 -6100
Lucky numbers between 6000 and 6100 are:
[6009, 6019, 6031, 6049, 6055, 6061, 6079, 6093]

\$ java -jar lucky.jar 6000 -6100 evenLucky
Lucky even numbers between 6000 and 6100 are:
[6018, 6020, 6022, 6026, 6036, 6038, 6050, 6058, 6074, 6090, 6092]

\$ java -jar lucky.jar 10000 , lucky
Lucky number 10000 = 115591

\$ java -jar lucky.jar 10000 , evenLucky
Lucky even number 10000 = 111842
```

## Mathematica/Wolfram Language

Save the following code in the file script.wls and execute the wolframscript from the command line:

`ClearAll[GetLuckies, GetEvenLuckies]GetLuckies[max_] := Module[{luckies, f, i},  luckies = Range[1, max, 2];  f[n_] := Block[{k = luckies[[n]]}, luckies = Delete[luckies, Table[{k}, {k, k, [email protected], k}]]];  i = 2;  While[i < Length[luckies],   f[i];   i++   ];  luckies  ]GetEvenLuckies[max_] := Module[{lst, i, len},  lst = Range[2, max, 2];  i = 2;  While[i <= (len = [email protected]) && (k = lst[[i]]) <= len,   lst = Drop[lst, {k, len, k}];   i++   ];  lst  ]GiveLucky[s_String] := GiveLucky[StringSplit[s, " "]]GiveLucky[args_List] := Module[{argc = Length[args], j, k, type},  If[argc > 3,   Print["Too many arguments"]   ,   If[argc == 0,    Print["Too few arguments"]    ,    Switch[argc, 1,     j = Interpreter["Integer"][args[[1]]];     If[! FailureQ[j],      If[j > 0,       [email protected][20 j][[j]]       ,       Print["j should be positive"]       ]      ,      Print["one argument that is not an integer"]      ]     , 2,     j = Interpreter["Integer"][args[[1]]];     k = Interpreter["Integer"][args[[2]]];     If[! FailureQ[j] \[And] ! FailureQ[k],      If[j > 0,       If[k > 0,        [email protected][20 k][[j ;; k]]        ,        [email protected][GetLuckies[-k], GreaterEqualThan[j]]        ]       ,       Print["j should be positive"]       ]      ,      Print["one of the two arguments is not an integer\[Ellipsis]"]      ]     , 3,     If[args[[2]] === ",",      j = Interpreter["Integer"][args[[1]]];      If[! FailureQ[j],       If[j > 0,        type = args[[3]];        If[MatchQ[type, "evenLucky" | "lucky"],         If[type === "evenLucky",          [email protected][20 j][[j]]          ,          [email protected][20 j][[j]]          ]         ,         Print["unknown type ", type]         ]        ,        Print["j should be positive"]        ]       ,       Print["j should be an integer"]       ]      ,      j = Interpreter["Integer"][args[[1]]];      k = Interpreter["Integer"][args[[2]]];      If[! FailureQ[j] \[And] ! FailureQ[k],       If[j > 0,        type = args[[3]];        If[k > 0,         If[MatchQ[type, "evenLucky" | "lucky"],          If[type === "evenLucky",           [email protected][20 k][[j ;; k]]           ,           [email protected][20 k][[j ;; k]]           ]          ,          Print["unknown type ", type]          ]         ,         If[MatchQ[type, "evenLucky" | "lucky"],          If[type === "evenLucky",           [email protected][GetEvenLuckies[-k], GreaterEqualThan[j]]           ,           [email protected][GetLuckies[-k], GreaterEqualThan[j]]           ]          ,          Print["unknown type ", type]          ]         ]        ,        Print["j should be positive"]        ]       ,       Print["one of the two arguments is not an integer\[Ellipsis]"]       ]      ]     ]    ]   ]  ]GiveLucky[[email protected]\$ScriptCommandLine]`
Output:
```wolframscript -file script.wls -args "1 20 lucky"
{1, 3, 7, 9, 13, 15, 21, 25, 31, 33, 37, 43, 49, 51, 63, 67, 69, 73, 75, 79}
wolframscript -file script.wls -args "1 20 evenLucky"
{2, 4, 6, 10, 12, 18, 20, 22, 26, 34, 36, 42, 44, 50, 52, 54, 58, 68, 70, 76}
wolframscript -file script.wls -args "6000 -6100"
{6009, 6019, 6031, 6049, 6055, 6061, 6079, 6093}
wolframscript -file script.wls -args "6000 -6100 evenLucky"
{6018, 6020, 6022, 6026, 6036, 6038, 6050, 6058, 6074, 6090, 6092}
wolframscript -file script.wls -args "10000 , lucky"
115591
wolframscript -file script.wls -args "10000 , evenLucky"
111842```

## Nim

For the generation of lucky numbers, we use the second Python algorithm, modified to return a sequence.

`import os, strformat, strutils type LuckyKind {.pure.} = enum Lucky = "lucky", EvenLucky = "evenlucky" const NoValue = 0   # Indicates that no value have been specified.  ##################################################################################################### Lucky numbers generation. func initLuckyNumbers(nelems: int; kind: LuckyKind): seq[int] =  ## Initialize a list of lucky numbers.  result = newSeqOfCap[int](nelems)  for i in 0..<nelems:    var k = i    for j in countdown(result.high, 1):      k = k * result[j] div (result[j] - 1)    result.add 2 * k + 1 + ord(kind)  ##################################################################################################### Printing. template name(kind: LuckyKind): string =  if kind == Lucky: "Lucky" else: "Even lucky" proc printSingle(j: int; kind: LuckyKind) =  ## Print the lucky number at a given index.  let luckySeq = initLuckyNumbers(j, kind)  echo &"{name(kind)} number at index {j} is {luckySeq[j - 1]}" proc printRange(j, k: int; kind: LuckyKind) =  ## print the luck numbers in a range of indexes.  let luckySeq = initLuckyNumbers(k, kind)  var list = &"{name(kind)} numbers at indexes {j} to {k} are: "  let start = list.len  for idx in (j - 1)..(k - 1):    list.addSep(", ", start)    list.add \$luckySeq[idx]  echo list proc printInRange(j, k: int; kind: LuckyKind) =  ## Print the lucky numbers in a range of values.  let luckySeq = initLuckyNumbers(k, kind)  # "k" is greater than needed.  var list = &"{name(kind)} numbers between {j} to {k} are: "  let start = list.len  for val in luckySeq:    if val > k: break    if val > j:      list.addSep(", ", start)      list.add \$val  echo list  ##################################################################################################### Command line parsing. proc parseCommandLine(): tuple[j, k: int; kind: LuckyKind] =  ## Parse the command line.   # Internal exception to catch invalid argument value.  type InvalidArgumentError = object of ValueError   template raiseError(message, value = "") =    ## Raise an InvalidArgumentError.    raise newException(InvalidArgumentError, message & value & '.')    result = (Novalue, Novalue, Lucky)   try:     if paramCount() notin 1..3: raiseError "Wrong number of arguments"     # First argument: "j" value.    let p1 = paramStr(1)    try:      result.j = parseInt(p1)      if result.j <= 0: raiseError "Expected a positive number, got: ", p1    except ValueError:      raiseError "Expected an integer, got: ", p1     # Second argument: "k" value or a comma.    if paramCount() > 1:      let p2 = paramStr(2)      if p2 == ",":        # Must be followed by the kind of lucky number.        if paramCount() != 3: raiseError "Missing kind argument"      else:        try:          result.k = parseInt(p2)          if result.k == 0: raiseError "Expected a non null number, got: ", p2        except ValueError:          raiseError "Expected an integer, got: ", p2     # Third argument: number kind.    if paramCount() == 3:      let p3 = paramStr(3)      try:        result.kind = parseEnum[LuckyKind](p3.toLowerAscii())      except ValueError:        raiseError "Wrong kind: ", p3   except InvalidArgumentError:    quit getCurrentExceptionMsg()  #———————————————————————————————————————————————————————————————————————————————————————————————————# Main program. let (j, k, kind) = parseCommandLine() if k == NoValue:  # Print jth value.  printSingle(j, kind) elif k > 0:  # Print jth to kth values.  printRange(j, k, kind) else:  # Print values in range j..(-k).  printInRange(j, -k, kind)`
Output:
```./lucky_numbers 1 20
Lucky numbers at indexes 1 to 20 are: 1, 3, 7, 9, 13, 15, 21, 25, 31, 33, 37, 43, 49, 51, 63, 67, 69, 73, 75, 79

./lucky_numbers 1 20 evenlucky
Even lucky numbers at indexes 1 to 20 are: 2, 4, 6, 10, 12, 18, 20, 22, 26, 34, 36, 42, 44, 50, 52, 54, 58, 68, 70, 76

./lucky_numbers 6000 -6100
Lucky numbers between 6000 to 6100 are: 6009, 6019, 6031, 6049, 6055, 6061, 6079, 6093

./lucky_numbers 6000 -6100 evenlucky
Even lucky numbers between 6000 to 6100 are: 6018, 6020, 6022, 6026, 6036, 6038, 6050, 6058, 6074, 6090, 6092

./lucky_numbers 10000 , lucky
Lucky number at index 10000 is 115591

./lucky_numbers 10000 , evenlucky
Even lucky number at index 10000 is 111842```

## Perl

The module `Perl6::GatherTake` emulates the Raku gather/take syntax, and allows us to access values from what acts (mostly) like a lazy list.

Translation of: Raku
`use Perl6::GatherTake; sub luck {my(\$a,\$b) = @_; gather {    my \$i = \$b;    my(@taken,@rotor,\$j);     take 0; # 0th index is a placeholder    push @taken, take \$a;     while () {        for (\$j = 0; \$j < @rotor; \$j++) {            --\$rotor[\$j] or last;        }        if (\$j < @rotor) {            \$rotor[\$j] = \$taken[\$j+1];        }        else {            take \$i;            push @taken, \$i;            push @rotor, \$i - @taken;        }        \$i += 2;    }}} # fiddle with user input\$j = shift || usage();\$k = shift || ',';\$l = shift || 'lucky';usage() unless \$k =~ /,|-?\d+/;usage() unless \$l =~ /^(even)?lucky\$/i;sub usage { print "Args must be:  j [,|k|-k] [lucky|evenlucky]\n" and exit } # seed the iteratormy \$lucky = \$l =~ /^l/i ? luck(1,3) : luck(2,4); # access values from 'lazy' listif (\$k eq ',') {    print \$lucky->[\$j]} elsif (\$k > \$j) {    print \$lucky->[\$_] . ' ' for \$j..\$k} elsif (\$k < 0) {    while () { last if abs(\$k) < \$lucky->[\$i++] } # must first extend the array    print join ' ', grep { \$_ >= \$j and \$_ <= abs(\$k) } @\$lucky} print "\n"`
Output:
```\$ ./lucky
Args must be:  j [,|k|-k] [lucky|evenlucky]
\$ ./lucky 20 , lucky
79
\$ ./lucky 20 , evenlucky
76
\$ ./lucky 1 20
1 3 7 9 13 15 21 25 31 33 37 43 49 51 63 67 69 73 75 79
\$ ./lucky 1 20 evenlucky
2 4 6 10 12 18 20 22 26 34 36 42 44 50 52 54 58 68 70 76
\$ ./lucky 6000 -6100
6009 6019 6031 6049 6055 6061 6079 6093
\$ ./lucky 6000 -6100 evenLucky
6018 6020 6022 6026 6036 6038 6050 6058 6074 6090 6092
\$ ./lucky 10000
115591
\$ ./lucky 10000 , EVENLUCKY
111842```

## Phix

`constant luckyMax = 120000 sequence lucky procedure filterLucky()    integer n = 2    while n<=length(lucky) do        integer m = lucky[n],                 l = m-1        for k=m+1 to length(lucky) do            if mod(k,m)!=0 then                l += 1                lucky[l] = lucky[k]            end if        end for        if l>=length(lucky) then exit end if        lucky = lucky[1..l]        n += 1    end whileend procedure constant helptxt = """   argument(s)   |  what is displayed======================================= j               |  jth lucky number j [,] lucky     |  jth lucky number j [,] evenLucky |  jth even lucky number j k             |  jth through kth (inclusive) lucky numbers j k lucky       |  jth through kth (inclusive) lucky numbers j k evenLucky   |  jth through kth (inclusive) even lucky numbers j -k            |  all lucky numbers in the range j to k j -k lucky      |  all lucky numbers in the range j to k j -k evenLucky  |  all even lucky numbers in the range j to k""" procedure fatal(string msg)    puts(1,msg)    puts(1,helptxt)    {} = wait_key()    abort(0)end procedure procedure main()    sequence cl = command_line()    integer j,k,l,m,n    bool single = true, range = true, odd = true    if length(cl)=2 then--      fatal("at least one argument must be supplied") -- (if preferred)        sequence tests = {"1 20",                          "1 20 evenLucky",                          "20 lucky",                          "20 evenLucky",                          "6000 -6100",                          "6000 -6100 evenLucky",                          "10000 lucky",                          "10000 evenLucky"}        -- (done this way to exercise the real command line handling)        if cl[1]=cl[2] then                     -- (compiled)            cl = cl[1..1]        elsif platform()=WINDOWS then           -- (and interpreted)            cl[1] = substitute(cl[1],"pw","p")  -- (pw.exe -> p.exe)        end if        for i=1 to length(cl) do            if find(' ',cl[i]) then cl[i] = sprintf("\"%s\"",{cl[i]}) end if        end for        for t=1 to length(tests) do            string cmd = join(append(cl,tests[t]))--          printf(1,"running %s\n",{cmd})            {} = system_exec(cmd)        end for        puts(1, "tests complete\n")         {} = wait_key()    else        cl = cl[3..\$] -- ({1,2} are {interperter,source} or {exe,exe})         --        -- Allow eg "lucky j , evenLucky" to be == "lucky j evenLucky"        --        if length(cl)=3 and cl[2]="," then cl[2..2] = {} end if         for i=1 to length(cl) do            string cli = cl[i]            if cli[1]<='9' then     -- (includes '-')                sequence d = scanf(cl[i],"%d")                if length(d)!=1 then                    fatal("unrecognised "&cli)                end if                if i>2 then                    fatal("too many numbers")                end if                n = d[1][1]                if i=1 then                    if n<1 then                        fatal("first argument must be a positive integer")                    end if                    j = n                else                     single = false                    if n<0 then                        range = false                        n = -n                    end if                    if n<j then                        fatal("second argument cannot be less than first")                    end if                    k = n                end if            else                l = find(cli,{"lucky","evenLucky"})                if l=0 then                    fatal("unrecognised "&cli)                end if                if i!=length(cl) then                    fatal(cli&" must be last parameter")                end if                odd = (l=1)            end if        end for         lucky = tagset(luckyMax,2-odd,2)        filterLucky()        printf(1,"Output when args are %s\n",{join(cl)})        string even = iff(odd?"":"even ")        if single then            if j>length(lucky) then                fatal(sprintf("the argument, %d, is too big", j))            end if            printf(1,"Lucky %snumber %d = %d\n",{even,j, lucky[j]})        elsif range then            if k>length(lucky) then                fatal(sprintf("the argument, %d, is too big", k))            end if            printf(1,"Lucky %snumbers %d to %d are: %s\n",{even,j,k,sprint(lucky[j..k])})        else            if j>lucky[\$] then                fatal("start of range is too big")            elsif k>lucky[\$] then                fatal("end of range is too big")            end if            m = abs(binary_search(j,lucky))            n = binary_search(k,lucky)            if n<0 then n = -n-1 end if            printf(1,"Lucky %snumbers between %d and %d are: %s\n", {even,j,k,sprint(lucky[m..n])})        end if    end ifend proceduremain()`
Output:
```Output when args are 1 20
Lucky numbers 1 to 20 are: {1,3,7,9,13,15,21,25,31,33,37,43,49,51,63,67,69,73,75,79}
Output when args are 1 20 evenLucky
Lucky even numbers 1 to 20 are: {2,4,6,10,12,18,20,22,26,34,36,42,44,50,52,54,58,68,70,76}
Output when args are 20 lucky
Lucky number 20 = 79
Output when args are 20 evenLucky
Lucky even number 20 = 76
Output when args are 6000 -6100
Lucky numbers between 6000 and 6100 are: {6009,6019,6031,6049,6055,6061,6079,6093}
Output when args are 6000 -6100 evenLucky
Lucky even numbers between 6000 and 6100 are: {6018,6020,6022,6026,6036,6038,6050,6058,6074,6090,6092}
Output when args are 10000 lucky
Lucky number 10000 = 115591
Output when args are 10000 evenLucky
Lucky even number 10000 = 111842
tests complete
```

## PicoLisp

`(off *Even) (de nn (Lst N)   (seek      '((L)         (when (car L) (=0 (dec 'N))) )      Lst ) ) (de lucky (B)   (let Lst (range (if *Even 2 1) B 2)      (for A (cdr Lst)         (for (L (nn Lst A) L (nn (cdr L) A))            (set L) ) )      (filter bool Lst) ) ) (argv . *Argv) # without validations(when (= "evenLucky" (last *Argv)) (on *Even))(setq *Lst (lucky 7000))(let (A (format (car *Argv))  B (format (cadr *Argv)))   (println      (if (lt0 B)         (filter '((N) (<= A N (abs B))) *Lst)         (head B (nth *Lst A)) ) ) )`
Output:
```\$ pil ./lucky.l 1 20
(1 3 7 9 13 15 21 25 31 33 37 43 49 51 63 67 69 73 75 79)
\$ pil ./lucky.l 1 20 evenLucky
(2 4 6 10 12 18 20 22 26 34 36 42 44 50 52 54 58 68 70 76)
\$ pil ./lucky.l 6000 -6100
(6009 6019 6031 6049 6055 6061 6079 6093)
\$ pil ./lucky.l 6000 -6100 evenLucky
(6018 6020 6022 6026 6036 6038 6050 6058 6074 6090 6092)```

## Python

The generator

`from __future__ import print_function def lgen(even=False, nmax=1000000):    start = 2 if even else 1    n, lst = 1, list(range(start, nmax + 1, 2))    lenlst = len(lst)    yield lst[0]    while n < lenlst and lst[n] < lenlst:        yield lst[n]        n, lst = n + 1, [j for i,j in enumerate(lst, 1) if i % lst[n]]        lenlst = len(lst)    # drain    for i in lst[n:]:        yield i`

The argument handler

`from itertools import isliceimport sys, re class ArgumentError(Exception):    passdef arghandler(argstring):    match_obj = re.match( r"""(?mx)    (?:      (?P<SINGLE>         (?: ^ (?P<SINGLEL> \d+ ) (?:  | \s , \s lucky ) \s* \$ )        |(?: ^ (?P<SINGLEE> \d+ ) (?:  | \s , \s evenLucky ) \s* \$ )      )     |(?P<KTH>         (?: ^ (?P<KTHL> \d+ \s \d+ ) (?:  | \s lucky ) \s* \$ )        |(?: ^ (?P<KTHE> \d+ \s \d+ ) (?:  | \s evenLucky ) \s* \$ )      )     |(?P<RANGE>         (?: ^ (?P<RANGEL> \d+ \s -\d+ ) (?:  | \s lucky ) \s* \$ )        |(?: ^ (?P<RANGEE> \d+ \s -\d+ ) (?:  | \s evenLucky ) \s* \$ )      )    )""", argstring)     if match_obj:        # Retrieve group(s) by name        SINGLEL = match_obj.group('SINGLEL')        SINGLEE = match_obj.group('SINGLEE')        KTHL = match_obj.group('KTHL')        KTHE = match_obj.group('KTHE')        RANGEL = match_obj.group('RANGEL')        RANGEE = match_obj.group('RANGEE')        if SINGLEL:             j = int(SINGLEL)            assert 0 < j < 10001, "Argument out of range"            print("Single %i'th lucky number:" % j, end=' ')            print( list(islice(lgen(), j-1, j))[0] )        elif SINGLEE:             j = int(SINGLEE)            assert 0 < j < 10001, "Argument out of range"            print("Single %i'th even lucky number:" % j, end=' ')            print( list(islice(lgen(even=True), j-1, j))[0] )        elif KTHL:             j, k = [int(num) for num in KTHL.split()]            assert 0 < j < 10001, "first argument out of range"            assert 0 < k < 10001 and k > j, "second argument out of range"            print("List of %i ... %i lucky numbers:" % (j, k), end=' ')            for n, luck in enumerate(lgen(), 1):                if n > k: break                if n >=j: print(luck, end = ', ')            print('')        elif KTHE:             j, k = [int(num) for num in KTHE.split()]            assert 0 < j < 10001, "first argument out of range"            assert 0 < k < 10001 and k > j, "second argument out of range"            print("List of %i ... %i even lucky numbers:" % (j, k), end=' ')            for n, luck in enumerate(lgen(even=True), 1):                if n > k: break                if n >=j: print(luck, end = ', ')            print('')        elif RANGEL:             j, k = [int(num) for num in RANGEL.split()]            assert 0 < j < 10001, "first argument out of range"            assert 0 < -k < 10001 and -k > j, "second argument out of range"            k = -k            print("List of lucky numbers in the range %i ... %i :" % (j, k), end=' ')            for n in lgen():                if n > k: break                if n >=j: print(n, end = ', ')            print('')        elif RANGEE:             j, k = [int(num) for num in RANGEE.split()]            assert 0 < j < 10001, "first argument out of range"            assert 0 < -k < 10001 and -k > j, "second argument out of range"            k = -k            print("List of even lucky numbers in the range %i ... %i :" % (j, k), end=' ')            for n in lgen(even=True):                if n > k: break                if n >=j: print(n, end = ', ')            print('')    else:        raise ArgumentError('''   Error Parsing Arguments!   Expected Arguments of the form (where j and k are integers):       j                #  Jth       lucky number      j  ,      lucky  #  Jth       lucky number      j  ,  evenLucky  #  Jth  even lucky number                       #      j  k             #  Jth  through  Kth (inclusive)       lucky numbers      j  k      lucky  #  Jth  through  Kth (inclusive)       lucky numbers      j  k  evenLucky  #  Jth  through  Kth (inclusive)  even lucky numbers                       #      j -k             #  all       lucky numbers in the range  j --? |k|      j -k      lucky  #  all       lucky numbers in the range  j --? |k|      j -k  evenLucky  #  all  even lucky numbers in the range  j --? |k|        ''') if __name__ == '__main__':    arghandler(' '.join(sys.argv[1:]))`
Output:
```# Output when arguments are: 1 20 lucky
List of 1 ... 20 lucky numbers: 1, 3, 7, 9, 13, 15, 21, 25, 31, 33, 37, 43, 49, 51, 63, 67, 69, 73, 75, 79,
# Output when arguments are: 1 20 evenLucky
List of 1 ... 20 even lucky numbers: 2, 4, 6, 10, 12, 18, 20, 22, 26, 34, 36, 42, 44, 50, 52, 54, 58, 68, 70, 76,
# Output when arguments are: 6000 -6100 lucky
List of lucky numbers in the range 6000 ... 6100 : 6009, 6019, 6031, 6049, 6055, 6061, 6079, 6093,
# Output when arguments are: 6000 -6100 evenLucky
List of even lucky numbers in the range 6000 ... 6100 : 6018, 6020, 6022, 6026, 6036, 6038, 6050, 6058, 6074, 6090, 6092,
# Output when arguments are: 10000
Single 10000'th lucky number: 115591
# Output when arguments are: 10000 , evenLucky
Single 10000'th even lucky number: 111842```

### Python: streaming lazy generator

The following streaming version of function lgen returns odd or even lucky numbers until reaching system limits. Instead of creating a bounded table and deleting elements, it uses the insight that after each iteration the remaining numbers are shuffled left, modifying their indices in a regular way. Reversing this process tracks the k'th lucky number in the final list back to its position in the initial list of integers, and hence determines its value without any need to build the table. The only storage requirement is for the list of numbers found so far.
Based on the algorithm at https://oeis.org/A000959/a000959.txt.

`from itertools import countdef lgen(even=False):    lucky = []    if not even:        yield 1    for k in count(1):        for l in reversed(lucky):            k = (k*l)//(l-1)        lucky.append(2*k+1 + even)        yield 2*k+1 + even `

## Raku

(formerly Perl 6)

`sub luck(\a,\b) {    gather {	my @taken = take a;	my @rotor;	my \$i = b; 	loop {	    loop (my \$j = 0; \$j < @rotor; \$j++) {		--@rotor[\$j] or last;	    }	    if \$j < @rotor {		@rotor[\$j] = @taken[\$j+1];	    }	    else {		push @taken, take \$i;		push @rotor, \$i - @taken;	    }	    \$i += 2;	}    }} constant @lucky = luck(1,3);constant @evenlucky = luck(2,4); subset Luck where m:i/^ 'even'? 'lucky' \$/; multi MAIN (Int \$num where * > 0) {    say @lucky[\$num-1];} multi MAIN (Int \$num where * > 0, ',', Luck \$howlucky = 'lucky') {    say @::(lc \$howlucky)[\$num-1];} multi MAIN (Int \$first where * > 0, Int \$last where * > 0, Luck \$howlucky = 'lucky') {    say @::(lc \$howlucky)[\$first-1 .. \$last - 1];} multi MAIN (Int \$min where * > 0, Int \$neg-max where * < 0, Luck \$howlucky = 'lucky') {    say grep * >= \$min, (@::(lc \$howlucky) ...^ * > abs \$neg-max);}`
Output:
```\$ ./lucky
Usage:
./lucky <num>
./lucky <num> , [<howlucky>]
./lucky <first> <last> [<howlucky>]
./lucky <min> <neg-max> [<howlucky>]
\$ ./lucky 20 , lucky
79
\$ ./lucky 20 , evenlucky
76
\$ ./lucky 1 20
1 3 7 9 13 15 21 25 31 33 37 43 49 51 63 67 69 73 75 79
\$ ./lucky 1 20 evenlucky
2 4 6 10 12 18 20 22 26 34 36 42 44 50 52 54 58 68 70 76
\$ ./lucky 6000 -6100
6009 6019 6031 6049 6055 6061 6079 6093
\$ ./lucky 6000 -6100 evenLucky
6018 6020 6022 6026 6036 6038 6050 6058 6074 6090 6092
\$ ./lucky 10000
115591
\$ ./lucky 10000 , EVENLUCKY
111842```

## REXX

This REXX version does extra error checking for the arguments.

`/*REXX program displays  lucky  or  evenLucky  integers   (numbers  or  a number range).*/parse arg bot top func _ .                       /*obtain required & optional arguments.*/if func==''  then func= 'lucky'                  /*Not specified?  Then use the default.*/s= left('s', bot\==top  &  top\==",")            /*plural results (or maybe not plural).*/say func  'number's":"   bot  top   '───►'   \$lucky(bot, top, func, _)exit 0                                           /*stick a fork in it,  we're all done. *//*──────────────────────────────────────────────────────────────────────────────────────*/\$lucky: arg x,y,f,?;   if y=='' | y==","  then y= x      /*obtain some arguments; set Y.*/        #= 0;          \$=;                    ny= y<0    /*set variable NOY: value range*/        if f==''  then f= 'LUCKY';   lucky= (f=="LUCKY") /*assume  LUCKY  if omitted.   */        if f\=='LUCKY' & f\=='EVENLUCKY'  then return  'function not valid: '     f        if arg()>3  &  ?\=''      then return  "too many arguments entered: "     ?        if x=''                   then return  "1st argument is missing."        if x<1                    then return  "1st argument isn't a positive integer: " x        if \datatype(x,'W')       then return  "1st argument isn't an integer: "  x        if \datatype(y,'W')       then return  "2nd argument isn't an integer: "  y        if x>ay                   then return  "2nd argument is less than 1st arg."        ay=abs(y); yL=ay; if y>0  then yL= y*10  + y + y /*adjust the upper  Y  limit.  */                                                         /* [↓]  build LUCKY | EVENLUCKY*/            do j=1  until j>=yL                          /*construct list pos. integers.*/            if j//2==(\lucky)  then iterate              /*EVENLUCKY? Use only even ints*/             if lucky  then if (j+1)//6==0  then iterate  /*prune       if  mod 6 ≡ zero.*/                                           else nop      /*balance the   IF-THEN  logic.*/                      else if  j   //8==0  then iterate  /*prune next  if  mod 8 ≡ zero.*/            #= # + 1                                     /*bump the counter of numbers. */            \$= \$ j                                       /*append integer to the \$ list.*/            end   /*j*/        q=0            do p=3  until  q=='';       q= word(\$, p)    /*start to prune  integer list.*/            if q>#  then leave                           /*if integer is too large, stop*/                                do j=#%q*q  by -q  to q  /*elide every  Qth  integer.   */                                \$= delword(\$, j, 1)      /*delete a particular number.  */                                #= # -1                  /*decrease the integer count.  */                                end   /*j*/              /*delete from the right side.  */            end   /*p*/        @.=                  do k=1;  parse var \$ q \$;       if q==''  then leave;       @.k= q                  end   /*k*/        @.0=k-1                  do m=1  for #                          /*restrict the found integers. */                  if (\ny  &  (m<x  |  m>ay))  |  (ny  &  (@.m<x | @.m>ay))  then @.m=                  end   /*m*/                            /* [↑]  a list of #s or a range*/        _=                  do b=1  for @.0;     _= _ @.b          /*construct a list of integers.*/                  end   /*b*/        return space(_)                                  /*remove superfluous blanks.   */`
output   when using the input of:     1   20   lucky
```lucky numbers: 1 20 ───► 1 3 7 9 13 15 21 25 31 33 37 43 49 51 63 67 69 73 75 79
```
output   when using the input of:     1   20   evenlucky
```evenLucky numbers: 1 20 ───► 2 4 6 10 12 18 20 22 26 34 36 42 44 50 52 54 58 68 70 76
```
output   when using the input of:     6000   -6100   lucky
```lucky numbers: 6000 -6100 ───► 6009 6019 6031 6049 6055 6061 6079 6093
```
output   when using the input of:     6000   -6100   evenLucky
```evenLucky numbers: 6000 -6100 ───► 6018 6020 6022 6026 6036 6038 6050 6058 6074 6090 6092
```
output   when using the input of:     10000
```lucky number: 10000 ───► 115591
```
output   when using the input of:     10000   ,   evenLucky
```evenLucky number: 10000 ───► 111842
```

## Ring

` # Project : Lucky and even lucky numbers lucky = list(50)dellucky = []for n = 1 to 50       lucky[n] = 2*n-1nextsee "the first 20 lucky numbers:" + nlluckynumbers(lucky)showarray(lucky)see nl lucky = list(50)dellucky = []for n = 1 to 50       lucky[n] = 2*nnextsee "the first 20 even lucky numbers:" + nlluckynumbers(lucky)showarray(lucky)see nl lucky = list(20000)dellucky = []for n = 1 to 10000      lucky[n] = 2*n-1nextsee "lucky numbers between 6,000 and 6,100:" + nlluckynumbers2(lucky)showarray2(lucky)see nl lucky = list(20000)dellucky = []for n = 1 to 10000      lucky[n] = 2*nnextsee "even lucky numbers between 6,000 and 6,100:" + nlluckynumbers2(lucky)showarray2(lucky)see nl func luckynumbers(lucky)      for n = 2 to len(lucky)           dellucky = []           for m = lucky[n] to len(lucky) step lucky[n]              add(dellucky, m)          next          for p = len(dellucky)  to 1 step -1              del(lucky, dellucky[p])          next      next func luckynumbers2(lucky)      for n = 2 to len(lucky)           dellucky = []           for m = lucky[n] to len(lucky) step lucky[n]              add(dellucky, m)          next          for p = len(dellucky)  to 1 step -1              del(lucky, dellucky[p])          next          if lucky[n] >= 6100             exit          oknext func showarray(vect)      see "["      svect = ""      for n = 1 to 20          svect = svect + vect[n] + ", "      next      svect = left(svect, len(svect) - 2)      see svect      see "]" + nl func showarray2(vect)      see "["      svect = ""      for n = 1 to len(vect)          if vect[n] >= 6000 and vect[n] <= 6100             svect = svect + vect[n] + ", "          ok      next      svect = left(svect, len(svect) - 2)      see svect      see "]" + nl `

Output:

```the first 20 lucky numbers:
[1, 3, 7, 9, 13, 15, 21, 25, 31, 33, 37, 43, 49, 51, 63, 67, 69, 73, 75, 79]

the first 20 even lucky numbers:
[2, 4, 6, 10, 12, 18, 20, 22, 26, 34, 36, 42, 44, 50, 52, 54, 58, 68, 70, 76]

lucky numbers between 6,000 and 6,100:
[6009, 6019, 6031, 6049, 6055, 6061, 6079, 6093]

even lucky numbers between 6,000 and 6,100:
[6018, 6020, 6022, 6026, 6036, 6038, 6050, 6058, 6074, 6090, 6092]
```

## Ruby

Translation of: Python
`def generator(even=false, nmax=1000000)  start = even ? 2 : 1  Enumerator.new do |y|    n = 1    ary = [0] + (start..nmax).step(2).to_a      # adds [0] to revise the 0 beginnings.    y << ary[n]    while (m = ary[n+=1]) < ary.size      y << m      (m...ary.size).step(m){|i| ary[i]=nil}      ary.compact!                              # remove nil    end    # drain    ary[n..-1].each{|i| y << i}    raise StopIteration  endend def lucky(argv)  j, k = argv[0].to_i, argv[1].to_i  mode = /even/i=~argv[2] ? :'even lucky' : :lucky  seq = generator(mode == :'even lucky')  ord = ->(n){"#{n}#{(n%100).between?(11,19) ? 'th' : %w[th st nd rd th th th th th th][n%10]}"}  if k.zero?    puts "#{ord[j]} #{mode} number: #{seq.take(j).last}"  elsif 0 < k    puts "#{ord[j]} through #{ord[k]} (inclusive) #{mode} numbers",         "  #{seq.take(k)[j-1..-1]}"  else    k = -k    ary = []    loop do      case num=seq.next      when 1...j      when j..k  then ary << num      else break      end    end    puts "all #{mode} numbers in the range #{j}..#{k}",         "  #{ary}"  endend if __FILE__ == \$0  lucky(ARGV)end`
Output:
```C:\>ruby lucky.rb 1 20
1st through 20th (inclusive) lucky numbers
[1, 3, 7, 9, 13, 15, 21, 25, 31, 33, 37, 43, 49, 51, 63, 67, 69, 73, 75, 79]

C:\>ruby lucky.rb 1 20 evenLucky
1st through 20th (inclusive) even lucky numbers
[2, 4, 6, 10, 12, 18, 20, 22, 26, 34, 36, 42, 44, 50, 52, 54, 58, 68, 70, 76]

C:\>ruby lucky.rb 6000 -6100 Lucky
all lucky numbers in the range 6000..6100
[6009, 6019, 6031, 6049, 6055, 6061, 6079, 6093]

C:\>ruby lucky.rb 6000 -6100 evenLucky
all even lucky numbers in the range 6000..6100
[6018, 6020, 6022, 6026, 6036, 6038, 6050, 6058, 6074, 6090, 6092]

C:\>ruby lucky.rb 10000
10000th lucky number: 115591

C:\>ruby lucky.rb 10000 , EVENLUCKY
10000th even lucky number: 111842
```

## Swift

Translation of: Python

The lucky numbers sequence:

`struct LuckyNumbers : Sequence, IteratorProtocol {  let even: Bool  let through: Int   private var drainI = 0  private var n = 0  private var lst: [Int]   init(even: Bool = false, through: Int = 1_000_000) {    self.even = even    self.through = through    self.lst = Array(stride(from: even ? 2 : 1, through: through, by: 2))  }   mutating func next() -> Int? {    guard n != 0 else {      defer { n += 1 }       return lst[0]    }     while n < lst.count && lst[n] < lst.count {      let retVal = lst[n]       lst = lst.enumerated().filter({ (\$0.offset + 1) % lst[n] != 0  }).map({ \$0.element })      n += 1       return retVal    }     if drainI == 0 {      lst = Array(lst.dropFirst(n))    }     while drainI < lst.count {      defer { drainI += 1 }       return lst[drainI]    }     return nil  }}`

The main file:

`let args = Array(CommandLine.arguments.dropFirst()) guard let sj = args.first, let j = Int(sj), j > 0, j <= 10_000 else {  fatalError("Incorrect j")} func evenString(_ even: Bool) -> String {  return even ? "even" : ""} func jLuckyNumber(_ j: Int, even: Bool) {  print("The \(j)th \(evenString(even)) lucky number is \(Array(LuckyNumbers(even: even))[j-1..<j].first!)")} func luckyNumbersKth(j: Int, k: Int, even: Bool) {  print("List of \(j) ... \(k) \(evenString(even)) lucky numbers: ", terminator: "")   for (offset, luck) in LuckyNumbers(even: even).lazy.enumerated() {    guard offset + 1 <= k else { break }     if offset + 1 >= j {      print(luck, terminator: ", ")    }  }   print()} func luckyNumbersRange(j: Int, k: Int, even: Bool) {  print("List of \(evenString(even)) lucky numbers in the range \(j) ... \(-k): ", terminator: "")   for lucky in LuckyNumbers(even: even).lazy {    guard lucky <= -k else { break }     if lucky >= j {      print(lucky, terminator: ", ")    }  }   print()} switch args.count {case 1:  jLuckyNumber(j, even: false)case 2:    switch Int(args.last!) {  case let k? where k > 0 && k <= 10_000 && k > j:    luckyNumbersKth(j: j, k: k, even: false)  case let k? where k < 0 && -k > j:    luckyNumbersRange(j: j, k: k, even: false)  case _:    fatalError("Bad args")  }case 3:  switch (Int(args[1]), args.last!) {  case (nil, "lucky"):    jLuckyNumber(j, even: false)  case (nil, "evenLucky"):    jLuckyNumber(j, even: true)  case let (k?, "lucky") where k > 0 && k <= 10_000 && k > j:    luckyNumbersKth(j: j, k: k, even: false)  case let (k?, "evenLucky") where k > 0 && k <= 10_000 && k > j:    luckyNumbersKth(j: j, k: k, even: true)  case let (k?, "lucky") where k < 0 && -k > j:    luckyNumbersRange(j: j, k: k, even: false)  case let (k?, "evenLucky") where k < 0 && -k > j:    luckyNumbersRange(j: j, k: k, even: true)  case _:    fatalError("Bad args")  }case _:  fatalError()}`
Output:
```\$ ./main 1 20 lucky
List of 1 ... 20  lucky numbers: 1, 3, 7, 9, 13, 15, 21, 25, 31, 33, 37, 43, 49, 51, 63, 67, 69, 73, 75, 79,
\$ ./main 1 20 evenLucky
List of 1 ... 20 even lucky numbers: 2, 4, 6, 10, 12, 18, 20, 22, 26, 34, 36, 42, 44, 50, 52, 54, 58, 68, 70, 76,
\$ ./main 6000 -6100 lucky
List of  lucky numbers in the range 6000 ... 6100: 6009, 6019, 6031, 6049, 6055, 6061, 6079, 6093,
\$ ./main 6000 -6100 evenLucky
List of even lucky numbers in the range 6000 ... 6100: 6018, 6020, 6022, 6026, 6036, 6038, 6050, 6058, 6074, 6090, 6092,
\$ ./main 10000
The 10000th  lucky number is 115591
\$ ./main 10000 , evenLucky
The 10000th even lucky number is 111842```

## Tcl

Works with: Tcl version 8.6
Translation of: Python
`#!/usr/bin/env tclsh8.6package require Tcl 8.6 proc lgen {{even false} {nmax 200000}} {    coroutine lgen.[incr ::lgen] apply {{start nmax} {	set n 1	for {set i \$start} {\$i <= \$nmax+1} {incr i 2} {lappend lst \$i}	yield [info coroutine]	yield [lindex \$lst 0]	while {\$n < [llength \$lst] && [lindex \$lst \$n] < [llength \$lst]} {	    yield [lindex \$lst \$n]	    set lst [set i 0;lmap j \$lst {		if {[incr i] % [lindex \$lst \$n]} {set j} else continue	    }]	    incr n	}	foreach i [lrange \$lst \$n end] {	    yield \$i	}    }} [expr {\$even ? 2 : 1}] \$nmax} proc collectIndices {generator from to} {    set result {}    for {set i 0} {\$i <= \$to} {incr i} {	set n [\$generator]	if {\$i >= \$from} {lappend result \$n}    }    rename \$generator {}    return \$result}proc collectValues {generator from to} {    set result {}    while 1 {	set n [\$generator]	if {\$n > \$to} break	if {\$n >= \$from} {lappend result \$n}    }    rename \$generator {}    return \$result} if {\$argc<1||\$argc>3} {    puts stderr "wrong # args: should be \"\$argv0 from ?to? ?evenOdd?\""    exit 1}lassign \$argv from to evenOddif {\$argc < 3} {set evenOdd lucky}if {\$argc < 2} {set to ,}if {![string is integer -strict \$from] || \$from < 1} {    puts stderr "\"from\" must be positive integer"    exit 1} elseif {\$to ne "," && (![string is integer -strict \$to] || \$to == 0)} {    puts stderr "\"to\" must be positive integer or comma"    exit 1} elseif {[set evenOdd [string tolower \$evenOdd]] ni {lucky evenlucky}} {    puts stderr "\"evenOdd\" must be \"lucky\" or \"evenLucky\""    exit 1}set l [lgen [expr {\$evenOdd eq "evenlucky"}]]set evenOdd [lindex {"lucky" "even lucky"} [expr {\$evenOdd eq "evenlucky"}]]if {\$to eq ","} {    puts "\$from'th \$evenOdd number = [collectIndices \$l [incr from -1] \$from]"} elseif {\$to < 0} {    set to [expr {-\$to}]    puts "all \$evenOdd numbers from \$from to \$to: [join [collectValues \$l \$from \$to] ,]"} else {    puts "\$from'th to \$to'th \$evenOdd numbers: [join [collectIndices \$l [incr from -1] [incr to -1]] ,]"}`
Output:
```bash\$ lucky.tcl 1 20
1'th to 20'th lucky numbers: 1,3,7,9,13,15,21,25,31,33,37,43,49,51,63,67,69,73,75,79
bash\$ lucky.tcl 1 20 evenLucky
1'th to 20'th even lucky numbers: 2,4,6,10,12,18,20,22,26,34,36,42,44,50,52,54,58,68,70,76
bash\$ lucky.tcl 6000 -6100
all lucky numbers from 6000 to 6100: 6009,6019,6031,6049,6055,6061,6079,6093
bash\$ lucky.tcl 6000 -6100 evenLucky
all even lucky numbers from 6000 to 6100: 6018,6020,6022,6026,6036,6038,6050,6058,6074,6090,6092
bash\$ lucky.tcl 10000
10000'th lucky number = 115591
bash\$ lucky.tcl 10000 , evenLucky
10000'th even lucky number = 111842
```

## Wren

Translation of: Kotlin
Library: Wren-trait
Library: Wren-str
`import "os" for Processimport "/trait" for Steppedimport "/str" for Str var luckyOdd  = List.filled(1e5, 0)var luckyEven = List.filled(1e5, 0) var init = Fn.new {    for (i in 0...1e5) {        luckyOdd[i]  = i*2 + 1        luckyEven[i] = i*2 + 2    }} var filterLuckyOdd = Fn.new {    var n = 2    while (n < luckyOdd.count) {        var m = luckyOdd[n-1]        var end = (luckyOdd.count/m).floor * m - 1        for (j in Stepped.descend(end..m-1, m)) luckyOdd.removeAt(j)        n = n + 1    }} var filterLuckyEven = Fn.new {    var n = 2    while (n < luckyEven.count) {        var m = luckyEven[n-1]        var end = (luckyEven.count/m).floor * m - 1        for (j in Stepped.descend(end..m-1, m)) luckyEven.removeAt(j)        n = n + 1    }} var printSingle = Fn.new { |j, odd|    if (odd) {        if (j >= luckyOdd.count) Fiber.abort("Argument is too big")        System.print("Lucky number %(j) = %(luckyOdd[j-1])")    } else {        if (j >= luckyEven.count) Fiber.abort("Argument is too big")        System.print("Lucky even number %(j) = %(luckyEven[j-1])")    }} var printRange = Fn.new { |j, k, odd|    if (odd) {        if (k >= luckyOdd.count) Fiber.abort("Argument is too big")        var rng = luckyOdd.skip(j-1).take(k-j+1).toList        System.print("Lucky numbers %(j) to %(k) are:\n %(rng)")    } else {        if (k >= luckyEven.count) Fiber.abort("Argument is too big")        var rng = luckyEven.skip(j-1).take(k-j+1).toList        System.print("Lucky even numbers %(j) to %(k) are:\n %(rng)")    }} var printBetween = Fn.new { |j, k, odd|    var rng = []    if (odd) {        var max = luckyOdd[-1]        if (j > max || k > max) {            Fiber.abort("At least one argument is too big")        }        for (num in luckyOdd) {            if (num >= j) {                if (num > k) break                rng.add(num)            }        }        System.print("Lucky numbers between %(j) and %(k) are:\n%(rng)")    } else {        var max = luckyEven[-1]        if (j > max || k > max) {            Fiber.abort("At least one argument is too big")        }        for (num in luckyEven) {            if (num >= j) {                if (num > k) break                rng.add(num)            }        }        System.print("Lucky even numbers between %(j) and %(k) are:\n%(rng)")    }} var args = Process.argumentsvar argsSize = args.countif (argsSize < 1 || argsSize > 3) Fiber.abort("There must be between 1 and 3 command line arguments")init.call()filterLuckyOdd.call()filterLuckyEven.call()var j = Num.fromString(args[0])if (j.type != Num || !j.isInteger || j < 1) Fiber.abort("First argument must be a positive integer")if (argsSize == 1) {    printSingle.call(j, true)    return} if (argsSize == 2) {    var k = Num.fromString(args[1])    if (k.type != Num || !k.isInteger) Fiber.abort("Second argument must be an integer")    if (k >= 0) {        if (j > k) Fiber.abort("Second argument can't be less than first")        printRange.call(j, k, true)    } else {        var l = -k        if (j > l) Fiber.abort("The second argument can't be less in absolute value than first")        printBetween.call(j, l, true)    }    return} args[2] = Str.lower(args[2])var odd = (args[2] == "lucky") ? true :          (args[2] == "evenlucky") ? false : Fiber.abort("Third argument is invalid") if (args[1] == ",") {    printSingle.call(j, odd)    return} var k = Num.fromString(args[1])if (!((k.type == Num && k.isInteger) || (k.type == String && k == ","))) {    Fiber.abort("Second argument must be an integer or a comma")}if (k >= 0) {    if (j > k) Fiber.abort("Second argument can't be less than first")    printRange.call(j, k, odd)} else {    var l = -k    if (j > l) Fiber.abort("The second argument can't be less in absolute value than first")    printBetween.call(j, l, odd)}`
Output:
```\$ wren lucky.wren 1 20
Lucky numbers 1 to 20 are:
[1, 3, 7, 9, 13, 15, 21, 25, 31, 33, 37, 43, 49, 51, 63, 67, 69, 73, 75, 79]

\$ wren lucky.wren 1 20 evenLucky
Lucky even numbers 1 to 20 are:
[2, 4, 6, 10, 12, 18, 20, 22, 26, 34, 36, 42, 44, 50, 52, 54, 58, 68, 70, 76]

\$ wren lucky.wren 6000 -6100
Lucky numbers between 6000 and 6100 are:
[6009, 6019, 6031, 6049, 6055, 6061, 6079, 6093]

\$ wren lucky.wren 6000 -6100 evenLucky
Lucky even numbers between 6000 and 6100 are:
[6018, 6020, 6022, 6026, 6036, 6038, 6050, 6058, 6074, 6090, 6092]

\$ wren lucky.wren 10000 , lucky
Lucky number 10000 = 115591

\$ wren lucky.wren 10000 , evenLucky
Lucky even number 10000 = 111842
```

## zkl

The lucky number generator works by chaining filters to a even or odd infinite sequence. So it acts like a sieve as each starting number percolates through the filters. It also means there are lots and lots of filters, which doesn't scale well but works for the examples.

`fcn lgen(a){   ns,idx:=[a..*,2],2;   vm.yield(ns.next());   while(1){      n:=ns.next();      vm.yield(n);      ns=ns.tweak(skipper.fp1(n,Ref(idx+=1)));  // tack on another filter   }}fcn skipper(n,skp,cnt){ z:=cnt.inc(); if(z%skp==0) Void.Skip else n  }`

The command line is a bit funky (by Unix standards) so we just hard code it and use exceptions (such as trying to convert "foo" to int) to show the options.

`cmdLineArgs,j,k,start:=vm.arglist,Void,Void,1;try{   j=cmdLineArgs[0].toInt();   na:=cmdLineArgs.len();   if(na>1){      if(cmdLineArgs[1]==",")         start=cmdLineArgs[2][0].toLower()=="e" and 2 or 1;      else{	 k=cmdLineArgs[1].toInt();	 if(na>2)	    start=cmdLineArgs[2][0].toLower()=="e" and 2 or 1;      }   }}catch{    fcn options{      "args: j | j , [even]lucky | j k [even]lucky | j -k [even]lucky"      .println();       System.exit(1);    }()}luckies:=Utils.Generator(lgen,start);try{   if(Void==k) luckies.drop(j-1).next().println();   else{      if(k>0) luckies.drop(j-1).walk(k-j+1).println();      else{ k=-k;	 while((n:=luckies.next())<j){}	 luckies.push(n);	 luckies.pump(List,'wrap(n){ n<=k and n or Void.Stop }).println();      }   }}catch(TheEnd){ options() }`
Output:
```\$ zkl lucky
args: j | j , [even]lucky | j k [even]lucky | j -k [even]lucky
\$ zkl lucky 1 20
L(1,3,7,9,13,15,21,25,31,33,37,43,49,51,63,67,69,73,75,79)
\$ zkl lucky 1 20 evenLucky
L(2,4,6,10,12,18,20,22,26,34,36,42,44,50,52,54,58,68,70,76)
\$ zkl lucky 6000 -6100
L(6009,6019,6031,6049,6055,6061,6079,6093)
\$ zkl lucky 6000 -6100 Even
L(6018,6020,6022,6026,6036,6038,6050,6058,6074,6090,6092)
\$ zkl lucky 10000
115591
\$ zkl lucky 10000 , evenLucky
111842
\$ zkl lucky 6000 -5000
L()
\$ zkl lucky 4 2
args: j | j , [even]lucky | j k [even]lucky | j -k [even]lucky
```