# Attractive numbers

Attractive numbers
You are encouraged to solve this task according to the task description, using any language you may know.

A number is an   attractive number   if the number of its prime factors (whether distinct or not) is also prime.

Example

The number   20,   whose prime decomposition is   2 × 2 × 5,   is an   attractive number   because the number of its prime factors   (3)   is also prime.

Show sequence items up to   120.

Reference

## AWK

` # syntax: GAWK -f ATTRACTIVE_NUMBERS.AWK# converted from CBEGIN {    limit = 120    printf("attractive numbers from 1-%d:\n",limit)    for (i=1; i<=limit; i++) {      n = count_prime_factors(i)      if (is_prime(n)) {        printf("%d ",i)      }    }    printf("\n")    exit(0)}function count_prime_factors(n,  count,f) {    f = 2    if (n == 1) { return(0) }    if (is_prime(n)) { return(1) }    while (1) {      if (!(n % f)) {        count++        n /= f        if (n == 1) { return(count) }        if (is_prime(n)) { f = n }      }      else if (f >= 3) { f += 2 }      else { f = 3 }    }}function is_prime(x,  i) {    if (x <= 1) {      return(0)    }    for (i=2; i<=int(sqrt(x)); i++) {      if (x % i == 0) {        return(0)      }    }    return(1)} `
Output:
```attractive numbers from 1-120:
4 6 8 9 10 12 14 15 18 20 21 22 25 26 27 28 30 32 33 34 35 38 39 42 44 45 46 48 49 50 51 52 55 57 58 62 63 65 66 68 69 70 72 74 75 76 77 78 80 82 85 86 87 91 92 93 94 95 98 99 102 105 106 108 110 111 112 114 115 116 117 118 119 120
```

## C

Translation of: Go
`#include <stdio.h> #define TRUE 1#define FALSE 0#define MAX 120 typedef int bool; bool is_prime(int n) {    int d = 5;    if (n < 2) return FALSE;    if (!(n % 2)) return n == 2;    if (!(n % 3)) return n == 3;    while (d *d <= n) {        if (!(n % d)) return FALSE;        d += 2;        if (!(n % d)) return FALSE;        d += 4;    }    return TRUE;} int count_prime_factors(int n) {    int count = 0, f = 2;    if (n == 1) return 0;    if (is_prime(n)) return 1;    while (TRUE) {        if (!(n % f)) {            count++;            n /= f;            if (n == 1) return count;            if (is_prime(n)) f = n;        }         else if (f >= 3) f += 2;        else f = 3;    }} int main() {        int i, n, count = 0;    printf("The attractive numbers up to and including %d are:\n", MAX);    for (i = 1; i <= MAX; ++i) {        n = count_prime_factors(i);        if (is_prime(n)) {            printf("%4d", i);            if (!(++count % 20)) printf("\n");        }    }    printf("\n");    return 0;  }`
Output:
```The attractive numbers up to and including 120 are:
4   6   8   9  10  12  14  15  18  20  21  22  25  26  27  28  30  32  33  34
35  38  39  42  44  45  46  48  49  50  51  52  55  57  58  62  63  65  66  68
69  70  72  74  75  76  77  78  80  82  85  86  87  91  92  93  94  95  98  99
102 105 106 108 110 111 112 114 115 116 117 118 119 120
```

## C++

Translation of: C
`#include <iostream>#include <iomanip> #define MAX 120 using namespace std; bool is_prime(int n) {       if (n < 2) return false;    if (!(n % 2)) return n == 2;    if (!(n % 3)) return n == 3;    int d = 5;    while (d *d <= n) {        if (!(n % d)) return false;        d += 2;        if (!(n % d)) return false;        d += 4;    }    return true;} int count_prime_factors(int n) {        if (n == 1) return 0;    if (is_prime(n)) return 1;    int count = 0, f = 2;    while (true) {        if (!(n % f)) {            count++;            n /= f;            if (n == 1) return count;            if (is_prime(n)) f = n;        }         else if (f >= 3) f += 2;        else f = 3;    }} int main() {    cout << "The attractive numbers up to and including " << MAX << " are:" << endl;    for (int i = 1, count = 0; i <= MAX; ++i) {        int n = count_prime_factors(i);        if (is_prime(n)) {            cout << setw(4) << i;            if (!(++count % 20)) cout << endl;        }    }    cout << endl;    return 0;}`
Output:
```The attractive numbers up to and including 120 are:
4   6   8   9  10  12  14  15  18  20  21  22  25  26  27  28  30  32  33  34
35  38  39  42  44  45  46  48  49  50  51  52  55  57  58  62  63  65  66  68
69  70  72  74  75  76  77  78  80  82  85  86  87  91  92  93  94  95  98  99
102 105 106 108 110 111 112 114 115 116 117 118 119 120
```

## C#

Translation of: D
`using System; namespace AttractiveNumbers {    class Program {        const int MAX = 120;         static bool IsPrime(int n) {            if (n < 2) return false;            if (n % 2 == 0) return n == 2;            if (n % 3 == 0) return n == 3;            int d = 5;            while (d * d <= n) {                if (n % d == 0) return false;                d += 2;                if (n % d == 0) return false;                d += 4;            }            return true;        }         static int PrimeFactorCount(int n) {            if (n == 1) return 0;            if (IsPrime(n)) return 1;            int count = 0;            int f = 2;            while (true) {                if (n % f == 0) {                    count++;                    n /= f;                    if (n == 1) return count;                    if (IsPrime(n)) f = n;                } else if (f >= 3) {                    f += 2;                } else {                    f = 3;                }            }        }         static void Main(string[] args) {            Console.WriteLine("The attractive numbers up to and including {0} are:", MAX);            int i = 1;            int count = 0;            while (i <= MAX) {                int n = PrimeFactorCount(i);                if (IsPrime(n)) {                    Console.Write("{0,4}", i);                    if (++count % 20 == 0) Console.WriteLine();                }                ++i;            }            Console.WriteLine();        }    }}`
Output:
```The attractive numbers up to and including 120 are:
4   6   8   9  10  12  14  15  18  20  21  22  25  26  27  28  30  32  33  34
35  38  39  42  44  45  46  48  49  50  51  52  55  57  58  62  63  65  66  68
69  70  72  74  75  76  77  78  80  82  85  86  87  91  92  93  94  95  98  99
102 105 106 108 110 111 112 114 115 116 117 118 119 120```

## D

Translation of: C++
`import std.stdio; enum MAX = 120; bool isPrime(int n) {    if (n < 2) return false;    if (n % 2 == 0) return n == 2;    if (n % 3 == 0) return n == 3;    int d = 5;    while (d * d <= n) {        if (n % d == 0) return false;        d += 2;        if (n % d == 0) return false;        d += 4;    }    return true;} int primeFactorCount(int n) {    if (n == 1) return 0;    if (isPrime(n)) return 1;    int count;    int f = 2;    while (true) {        if (n % f == 0) {            count++;            n /= f;            if (n == 1) return count;            if (isPrime(n)) f = n;        } else if (f >= 3) {            f += 2;        } else {            f = 3;        }    }} void main() {    writeln("The attractive numbers up to and including ", MAX, " are:");    int i = 1;    int count;    while (i <= MAX) {        int n = primeFactorCount(i);        if (isPrime(n)) {            writef("%4d", i);            if (++count % 20 == 0) writeln;        }        ++i;    }    writeln;}`
Output:
```The attractive numbers up to and including 120 are:
4   6   8   9  10  12  14  15  18  20  21  22  25  26  27  28  30  32  33  34
35  38  39  42  44  45  46  48  49  50  51  52  55  57  58  62  63  65  66  68
69  70  72  74  75  76  77  78  80  82  85  86  87  91  92  93  94  95  98  99
102 105 106 108 110 111 112 114 115 116 117 118 119 120```

## Factor

Works with: Factor version 0.99
`USING: formatting grouping io math.primes math.primes.factorsmath.ranges sequences ; "The attractive numbers up to and including 120 are:" print120 [1,b] [ factors length prime? ] filter 20 <groups>[ [ "%4d" printf ] each nl ] each`
Output:
```The attractive numbers up to and including 120 are:
4   6   8   9  10  12  14  15  18  20  21  22  25  26  27  28  30  32  33  34
35  38  39  42  44  45  46  48  49  50  51  52  55  57  58  62  63  65  66  68
69  70  72  74  75  76  77  78  80  82  85  86  87  91  92  93  94  95  98  99
102 105 106 108 110 111 112 114 115 116 117 118 119 120
```

## FreeBASIC

Translation of: D
` Const limite = 120 Declare Function esPrimo(n As Integer) As BooleanDeclare Function ContandoFactoresPrimos(n As Integer) As Integer Function esPrimo(n As Integer) As Boolean    If n < 2 Then Return false    If n Mod 2 = 0 Then Return n = 2    If n Mod 3 = 0 Then Return n = 3    Dim As Integer d = 5    While d * d <= n        If n Mod d = 0 Then Return false        d += 2        If n Mod d = 0 Then Return false        d += 4    Wend    Return trueEnd Function Function ContandoFactoresPrimos(n As Integer) As Integer    If n = 1 Then Return false    If esPrimo(n) Then Return true    Dim As Integer f = 2, contar = 0    While true        If n Mod f = 0 Then            contar += 1            n = n / f            If n = 1 Then Return contar            If esPrimo(n) Then f = n        Elseif f >= 3 Then            f += 2        Else             f = 3        End If    WendEnd Function ' Mostrar la sucencia de números atractivos hasta 120.Dim As Integer i = 1, longlinea = 0 Print "Los numeros atractivos hasta e incluyendo"; limite; " son: "While i <= limite    Dim As Integer n = ContandoFactoresPrimos(i)    If esPrimo(n) Then        Print Using "####"; i;        longlinea += 1: If longlinea Mod 20 = 0 Then Print ""    End If    i += 1WendEnd `
Output:
```Los numeros atractivos hasta e incluyendo 120 son:
4   6   8   9  10  12  14  15  18  20  21  22  25  26  27  28  30  32  33  34
35  38  39  42  44  45  46  48  49  50  51  52  55  57  58  62  63  65  66  68
69  70  72  74  75  76  77  78  80  82  85  86  87  91  92  93  94  95  98  99
102 105 106 108 110 111 112 114 115 116 117 118 119 120
```

## Go

Simple functions to test for primality and to count prime factors suffice here.

`package main import "fmt" func isPrime(n int) bool {    switch {    case n < 2:        return false    case n%2 == 0:        return n == 2    case n%3 == 0:        return n == 3    default:        d := 5        for d*d <= n {            if n%d == 0 {                return false            }            d += 2            if n%d == 0 {                return false            }            d += 4        }        return true    }} func countPrimeFactors(n int) int {    switch {    case n == 1:        return 0    case isPrime(n):        return 1    default:        count, f := 0, 2        for {            if n%f == 0 {                count++                n /= f                if n == 1 {                    return count                }                if isPrime(n) {                    f = n                }            } else if f >= 3 {                f += 2            } else {                f = 3            }        }        return count    }} func main() {    const max = 120    fmt.Println("The attractive numbers up to and including", max, "are:")    count := 0    for i := 1; i <= max; i++ {        n := countPrimeFactors(i)        if isPrime(n) {            fmt.Printf("%4d", i)            count++            if count % 20 == 0 {                fmt.Println()            }        }           }    fmt.Println()}`
Output:
```The attractive numbers up to and including 120 are:
4   6   8   9  10  12  14  15  18  20  21  22  25  26  27  28  30  32  33  34
35  38  39  42  44  45  46  48  49  50  51  52  55  57  58  62  63  65  66  68
69  70  72  74  75  76  77  78  80  82  85  86  87  91  92  93  94  95  98  99
102 105 106 108 110 111 112 114 115 116 117 118 119 120
```

## Groovy

Translation of: Java
`class AttractiveNumbers {    static boolean isPrime(int n) {        if (n < 2) return false        if (n % 2 == 0) return n == 2        if (n % 3 == 0) return n == 3        int d = 5        while (d * d <= n) {            if (n % d == 0) return false            d += 2            if (n % d == 0) return false            d += 4        }        return true    }     static int countPrimeFactors(int n) {        if (n == 1) return 0        if (isPrime(n)) return 1        int count = 0, f = 2        while (true) {            if (n % f == 0) {                count++                n /= f                if (n == 1) return count                if (isPrime(n)) f = n            } else if (f >= 3) f += 2            else f = 3        }    }     static void main(String[] args) {        final int max = 120        printf("The attractive numbers up to and including %d are:\n", max)        int count = 0        for (int i = 1; i <= max; ++i) {            int n = countPrimeFactors(i)            if (isPrime(n)) {                printf("%4d", i)                if (++count % 20 == 0) println()            }        }        println()    }}`
Output:
```The attractive numbers up to and including 120 are:
4   6   8   9  10  12  14  15  18  20  21  22  25  26  27  28  30  32  33  34
35  38  39  42  44  45  46  48  49  50  51  52  55  57  58  62  63  65  66  68
69  70  72  74  75  76  77  78  80  82  85  86  87  91  92  93  94  95  98  99
102 105 106 108 110 111 112 114 115 116 117 118 119 120```

`import Data.Numbers.Primesimport Data.Bool (bool) attractiveNumbers :: [Integer]attractiveNumbers =  [1 ..] >>= (bool [] . return) <*> (isPrime . length . primeFactors) main :: IO ()main = print \$ takeWhile (<= 120) attractiveNumbers`

Or equivalently, as a list comprehension:

`import Data.Numbers.Primes attractiveNumbers :: [Integer]attractiveNumbers =  [ x  | x <- [1 ..]   , isPrime (length (primeFactors x)) ] main :: IO ()main = print \$ takeWhile (<= 120) attractiveNumbers`

Or simply:

`import Data.Numbers.Primes attractiveNumbers :: [Integer]attractiveNumbers =  filter    (isPrime . length . primeFactors)    [1 ..] main :: IO ()main = print \$ takeWhile (<= 120) attractiveNumbers`
Output:
`[4,6,8,9,10,12,14,15,18,20,21,22,25,26,27,28,30,32,33,34,35,38,39,42,44,45,46,48,49,50,51,52,55,57,58,62,63,65,66,68,69,70,72,74,75,76,77,78,80,82,85,86,87,91,92,93,94,95,98,99,102,105,106,108,110,111,112,114,115,116,117,118,119,120]`

## Java

Translation of: C
`public class Attractive {     static boolean is_prime(int n) {        if (n < 2) return false;        if (n % 2 == 0) return n == 2;        if (n % 3 == 0) return n == 3;        int d = 5;        while (d *d <= n) {            if (n % d == 0) return false;            d += 2;            if (n % d == 0) return false;            d += 4;        }        return true;    }     static int count_prime_factors(int n) {        if (n == 1) return 0;        if (is_prime(n)) return 1;        int count = 0, f = 2;        while (true) {            if (n % f == 0) {                count++;                n /= f;                if (n == 1) return count;                if (is_prime(n)) f = n;            }            else if (f >= 3) f += 2;            else f = 3;        }    }     public static void main(String[] args) {        final int max = 120;        System.out.printf("The attractive numbers up to and including %d are:\n", max);        for (int i = 1, count = 0; i <= max; ++i) {            int n = count_prime_factors(i);            if (is_prime(n)) {                System.out.printf("%4d", i);                if (++count % 20 == 0) System.out.println();            }        }        System.out.println();    }}`
Output:
```The attractive numbers up to and including 120 are:
4   6   8   9  10  12  14  15  18  20  21  22  25  26  27  28  30  32  33  34
35  38  39  42  44  45  46  48  49  50  51  52  55  57  58  62  63  65  66  68
69  70  72  74  75  76  77  78  80  82  85  86  87  91  92  93  94  95  98  99
102 105 106 108 110 111 112 114 115 116 117 118 119 120
```

## Julia

`using Primes # oneliner is println("The attractive numbers from 1 to 120 are:\n", filter(x -> isprime(sum(values(factor(x)))), 1:120)) isattractive(n) = isprime(sum(values(factor(n)))) printattractive(m, n) = println("The attractive numbers from \$m to \$n are:\n", filter(isattractive, m:n)) printattractive(1, 120) `
Output:
```The attractive numbers from 1 to 120 are:
[4, 6, 8, 9, 10, 12, 14, 15, 18, 20, 21, 22, 25, 26, 27, 28, 30, 32, 33, 34, 35, 38, 39, 42, 44, 45, 46, 48, 49, 50, 51, 52, 55, 57, 58, 62, 63, 65, 66, 68, 69, 70, 72, 74, 75, 76, 77, 78, 80, 82, 85, 86, 87, 91, 92, 93, 94, 95, 98, 99, 102, 105, 106, 108, 110, 111, 112, 114, 115, 116, 117, 118, 119, 120]
```

## Kotlin

Translation of: Go
`// Version 1.3.21 const val MAX = 120 fun isPrime(n: Int) : Boolean {    if (n < 2) return false    if (n % 2 == 0) return n == 2    if (n % 3 == 0) return n == 3    var d : Int = 5    while (d * d <= n) {        if (n % d == 0) return false        d += 2        if (n % d == 0) return false        d += 4    }    return true} fun countPrimeFactors(n: Int) =    when {        n == 1  -> 0        isPrime(n) -> 1        else -> {            var nn = n            var count = 0            var f = 2            while (true) {                if (nn % f == 0) {                    count++                    nn /= f                    if (nn == 1) break                    if (isPrime(nn)) f = nn                } else if (f >= 3) {                    f += 2                } else {                    f = 3                }            }            count        }    } fun main() {    println("The attractive numbers up to and including \$MAX are:")    var count = 0    for (i in 1..MAX) {        val n = countPrimeFactors(i)        if (isPrime(n)) {            System.out.printf("%4d", i)            if (++count % 20 == 0) println()        }    }    println()}`
Output:
```The attractive numbers up to and including 120 are:
4   6   8   9  10  12  14  15  18  20  21  22  25  26  27  28  30  32  33  34
35  38  39  42  44  45  46  48  49  50  51  52  55  57  58  62  63  65  66  68
69  70  72  74  75  76  77  78  80  82  85  86  87  91  92  93  94  95  98  99
102 105 106 108 110 111 112 114 115 116 117 118 119 120
```

## LLVM

`; This is not strictly LLVM, as it uses the C library function "printf".; LLVM does not provide a way to print values, so the alternative would be; to just load the string into memory, and that would be boring. \$"ATTRACTIVE_STR" = comdat any\$"FORMAT_NUMBER" = comdat any\$"NEWLINE_STR" = comdat any @"ATTRACTIVE_STR" = linkonce_odr unnamed_addr constant [52 x i8] c"The attractive numbers up to and including %d are:\0A\00", comdat, align 1@"FORMAT_NUMBER" = linkonce_odr unnamed_addr constant [4 x i8] c"%4d\00", comdat, align 1@"NEWLINE_STR" = linkonce_odr unnamed_addr constant [2 x i8] c"\0A\00", comdat, align 1 ;--- The declaration for the external C printf function.declare i32 @printf(i8*, ...) ; Function Attrs: noinline nounwind optnone uwtabledefine zeroext i1 @is_prime(i32) #0 {  %2 = alloca i1, align 1               ;-- allocate return value  %3 = alloca i32, align 4              ;-- allocate n  %4 = alloca i32, align 4              ;-- allocate d  store i32 %0, i32* %3, align 4        ;-- store local copy of n  store i32 5, i32* %4, align 4         ;-- store 5 in d  %5 = load i32, i32* %3, align 4       ;-- load n  %6 = icmp slt i32 %5, 2               ;-- n < 2  br i1 %6, label %nlt2, label %niseven nlt2:  store i1 false, i1* %2, align 1       ;-- store false in return value  br label %exit niseven:  %7 = load i32, i32* %3, align 4       ;-- load n  %8 = srem i32 %7, 2                   ;-- n % 2  %9 = icmp ne i32 %8, 0                ;-- (n % 2) != 0  br i1 %9, label %odd, label %even even:  %10 = load i32, i32* %3, align 4      ;-- load n  %11 = icmp eq i32 %10, 2              ;-- n == 2  store i1 %11, i1* %2, align 1         ;-- store (n == 2) in return value  br label %exit odd:  %12 = load i32, i32* %3, align 4      ;-- load n  %13 = srem i32 %12, 3                 ;-- n % 3  %14 = icmp ne i32 %13, 0              ;-- (n % 3) != 0  br i1 %14, label %loop, label %div3 div3:  %15 = load i32, i32* %3, align 4      ;-- load n  %16 = icmp eq i32 %15, 3              ;-- n == 3  store i1 %16, i1* %2, align 1         ;-- store (n == 3) in return value  br label %exit loop:  %17 = load i32, i32* %4, align 4      ;-- load d  %18 = load i32, i32* %4, align 4      ;-- load d  %19 = mul nsw i32 %17, %18            ;-- d * d  %20 = load i32, i32* %3, align 4      ;-- load n  %21 = icmp sle i32 %19, %20           ;-- (d * d) <= n  br i1 %21, label %first, label %prime first:  %22 = load i32, i32* %3, align 4      ;-- load n  %23 = load i32, i32* %4, align 4      ;-- load d  %24 = srem i32 %22, %23               ;-- n % d  %25 = icmp ne i32 %24, 0              ;-- (n % d) != 0  br i1 %25, label %second, label %notprime second:  %26 = load i32, i32* %4, align 4      ;-- load d  %27 = add nsw i32 %26, 2              ;-- increment d by 2  store i32 %27, i32* %4, align 4       ;-- store d  %28 = load i32, i32* %3, align 4      ;-- load n  %29 = load i32, i32* %4, align 4      ;-- load d  %30 = srem i32 %28, %29               ;-- n % d  %31 = icmp ne i32 %30, 0              ;-- (n % d) != 0  br i1 %31, label %loop_end, label %notprime loop_end:  %32 = load i32, i32* %4, align 4      ;-- load d  %33 = add nsw i32 %32, 4              ;-- increment d by 4  store i32 %33, i32* %4, align 4       ;-- store d  br label %loop notprime:  store i1 false, i1* %2, align 1       ;-- store false in return value  br label %exit prime:  store i1 true, i1* %2, align 1        ;-- store true in return value  br label %exit exit:  %34 = load i1, i1* %2, align 1        ;-- load return value  ret i1 %34} ; Function Attrs: noinline nounwind optnone uwtabledefine i32 @count_prime_factors(i32) #0 {  %2 = alloca i32, align 4                      ;-- allocate return value  %3 = alloca i32, align 4                      ;-- allocate n  %4 = alloca i32, align 4                      ;-- allocate count  %5 = alloca i32, align 4                      ;-- allocate f  store i32 %0, i32* %3, align 4                ;-- store local copy of n  store i32 0, i32* %4, align 4                 ;-- store zero in count  store i32 2, i32* %5, align 4                 ;-- store 2 in f  %6 = load i32, i32* %3, align 4               ;-- load n  %7 = icmp eq i32 %6, 1                        ;-- n == 1  br i1 %7, label %eq1, label %ne1 eq1:  store i32 0, i32* %2, align 4                 ;-- store zero in return value  br label %exit ne1:  %8 = load i32, i32* %3, align 4               ;-- load n  %9 = call zeroext i1 @is_prime(i32 %8)        ;-- is n prime?  br i1 %9, label %prime, label %loop prime:  store i32 1, i32* %2, align 4                 ;-- store a in return value  br label %exit loop:  %10 = load i32, i32* %3, align 4              ;-- load n  %11 = load i32, i32* %5, align 4              ;-- load f  %12 = srem i32 %10, %11                       ;-- n % f  %13 = icmp ne i32 %12, 0                      ;-- (n % f) != 0  br i1 %13, label %br2, label %br1 br1:  %14 = load i32, i32* %4, align 4              ;-- load count  %15 = add nsw i32 %14, 1                      ;-- increment count  store i32 %15, i32* %4, align 4               ;-- store count  %16 = load i32, i32* %5, align 4              ;-- load f  %17 = load i32, i32* %3, align 4              ;-- load n  %18 = sdiv i32 %17, %16                       ;-- n / f  store i32 %18, i32* %3, align 4               ;-- n = n / f  %19 = load i32, i32* %3, align 4              ;-- load n  %20 = icmp eq i32 %19, 1                      ;-- n == 1  br i1 %20, label %br1_1, label %br1_2 br1_1:  %21 = load i32, i32* %4, align 4              ;-- load count  store i32 %21, i32* %2, align 4               ;-- store the count in the return value  br label %exit br1_2:  %22 = load i32, i32* %3, align 4              ;-- load n  %23 = call zeroext i1 @is_prime(i32 %22)      ;-- is n prime?  br i1 %23, label %br1_3, label %loop br1_3:  %24 = load i32, i32* %3, align 4              ;-- load n  store i32 %24, i32* %5, align 4               ;-- f = n  br label %loop br2:  %25 = load i32, i32* %5, align 4              ;-- load f  %26 = icmp sge i32 %25, 3                     ;-- f >= 3  br i1 %26, label %br2_1, label %br3 br2_1:  %27 = load i32, i32* %5, align 4              ;-- load f  %28 = add nsw i32 %27, 2                      ;-- increment f by 2  store i32 %28, i32* %5, align 4               ;-- store f  br label %loop br3:  store i32 3, i32* %5, align 4                 ;-- store 3 in f  br label %loop exit:  %29 = load i32, i32* %2, align 4              ;-- load return value  ret i32 %29} ; Function Attrs: noinline nounwind optnone uwtabledefine i32 @main() #0 {  %1 = alloca i32, align 4                      ;-- allocate i  %2 = alloca i32, align 4                      ;-- allocate n  %3 = alloca i32, align 4                      ;-- count  store i32 0, i32* %3, align 4                 ;-- store zero in count  %4 = call i32 (i8*, ...) @printf(i8* getelementptr inbounds ([52 x i8], [52 x i8]* @"ATTRACTIVE_STR", i32 0, i32 0), i32 120)  store i32 1, i32* %1, align 4                 ;-- store 1 in i  br label %loop loop:  %5 = load i32, i32* %1, align 4               ;-- load i  %6 = icmp sle i32 %5, 120                     ;-- i <= 120  br i1 %6, label %loop_body, label %exit loop_body:  %7 = load i32, i32* %1, align 4               ;-- load i  %8 = call i32 @count_prime_factors(i32 %7)    ;-- count factors of i  store i32 %8, i32* %2, align 4                ;-- store factors in n  %9 = call zeroext i1 @is_prime(i32 %8)        ;-- is n prime?  br i1 %9, label %prime_branch, label %loop_inc prime_branch:  %10 = load i32, i32* %1, align 4              ;-- load i  %11 = call i32 (i8*, ...) @printf(i8* getelementptr inbounds ([4 x i8], [4 x i8]* @"FORMAT_NUMBER", i32 0, i32 0), i32 %10)  %12 = load i32, i32* %3, align 4              ;-- load count  %13 = add nsw i32 %12, 1                      ;-- increment count  store i32 %13, i32* %3, align 4               ;-- store count  %14 = srem i32 %13, 20                        ;-- count % 20  %15 = icmp ne i32 %14, 0                      ;-- (count % 20) != 0  br i1 %15, label %loop_inc, label %row_end row_end:  %16 = call i32 (i8*, ...) @printf(i8* getelementptr inbounds ([2 x i8], [2 x i8]* @"NEWLINE_STR", i32 0, i32 0))  br label %loop_inc loop_inc:  %17 = load i32, i32* %1, align 4              ;-- load i  %18 = add nsw i32 %17, 1                      ;-- increment i  store i32 %18, i32* %1, align 4               ;-- store i  br label %loop exit:  %19 = call i32 (i8*, ...) @printf(i8* getelementptr inbounds ([2 x i8], [2 x i8]* @"NEWLINE_STR", i32 0, i32 0))  ret i32 0} attributes #0 = { noinline nounwind optnone uwtable "correctly-rounded-divide-sqrt-fp-math"="false" "disable-tail-calls"="false" "less-precise-fpmad"="false" "no-frame-pointer-elim"="false" "no-infs-fp-math"="false" "no-jump-tables"="false" "no-nans-fp-math"="false" "no-signed-zeros-fp-math"="false" "no-trapping-math"="false" "stack-protector-buffer-size"="8" "target-cpu"="x86-64" "target-features"="+fxsr,+mmx,+sse,+sse2,+x87" "unsafe-fp-math"="false" "use-soft-float"="false" }`
Output:
```The attractive numbers up to and including 120 are:
4   6   8   9  10  12  14  15  18  20  21  22  25  26  27  28  30  32  33  34
35  38  39  42  44  45  46  48  49  50  51  52  55  57  58  62  63  65  66  68
69  70  72  74  75  76  77  78  80  82  85  86  87  91  92  93  94  95  98  99
102 105 106 108 110 111 112 114 115 116 117 118 119 120```

## Maple

`attractivenumbers := proc(n::posint)local an, i;an :=[]:for i from 1 to n do    if isprime(NumberTheory:-NumberOfPrimeFactors(i)) then        an := [op(an), i]:    end if:end do:end proc:attractivenumbers(120);`
Output:
`[4, 6, 8, 9, 10, 12, 14, 15, 18, 20, 21, 22, 25, 26, 27, 28, 30, 32, 33, 34, 35, 38, 39, 42, 44, 45, 46, 48, 49, 50, 51, 52, 55, 57, 58, 62, 63, 65, 66, 68, 69, 70, 72, 74, 75, 76, 77, 78, 80, 82, 85, 86, 87, 91, 92, 93, 94, 95, 98, 99, 102, 105, 106, 108, 110, 111, 112, 114, 115, 116, 117, 118, 119, 120]`

## Perl

Library: ntheory
`use ntheory <is_prime factor>; is_prime +factor \$_ and print "\$_ " for 1..120;`
Output:
`4 6 8 9 10 12 14 15 18 20 21 22 25 26 27 28 30 32 33 34 35 38 39 42 44 45 46 48 49 50 51 52 55 57 58 62 63 65 66 68 69 70 72 74 75 76 77 78 80 82 85 86 87 91 92 93 94 95 98 99 102 105 106 108 110 111 112 114 115 116 117 118 119 120`

## Perl 6

Works with: Rakudo version 2019.03

This algorithm is concise but not really well suited to finding large quantities of consecutive attractive numbers. It works, but isn't especially speedy. More than a hundred thousand or so gets tedious. There are other, much faster (though more verbose) algorithms that could be used. This algorithm is well suited to finding arbitrary attractive numbers though.

`use Lingua::EN::Numbers;use ntheory:from<Perl5> <factor is_prime>; sub display (\$n,\$m) { (\$n..\$m).grep: (~*).&factor.elems.&is_prime } sub count (\$n,\$m) { +(\$n..\$m).grep: (~*).&factor.elems.&is_prime } # The Taskput "Attractive numbers from 1 to 120:\n" ~display(1, 120)».fmt("%3d").rotor(20, :partial).join: "\n"; # Robusto!for 1, 1000,  1, 10000, 1, 100000, 2**73 + 1, 2**73 + 100 -> \$a, \$b {    put "\nCount of attractive numbers from {comma \$a} to {comma \$b}:\n" ~    comma count \$a, \$b}`
Output:
```Attractive numbers from 1 to 120:
4   6   8   9  10  12  14  15  18  20  21  22  25  26  27  28  30  32  33  34
35  38  39  42  44  45  46  48  49  50  51  52  55  57  58  62  63  65  66  68
69  70  72  74  75  76  77  78  80  82  85  86  87  91  92  93  94  95  98  99
102 105 106 108 110 111 112 114 115 116 117 118 119 120

Count of attractive numbers from 1 to 1,000:
636

Count of attractive numbers from 1 to 10,000:
6,396

Count of attractive numbers from 1 to 100,000:
63,255

Count of attractive numbers from 9,444,732,965,739,290,427,393 to 9,444,732,965,739,290,427,492:
58```

## Phix

`function attractive(integer lim)    sequence s = {}    for i=1 to lim do        integer n = length(prime_factors(i,true))        if is_prime(n) then s &= i end if    end for    return send functionsequence s = attractive(120)printf(1,"There are %d attractive numbers up to and including %d:\n",{length(s),120})pp(s,{pp_IntCh,false})for i=3 to 5 do    integer p = power(10,i)    printf(1,"There are %,d attractive numbers up to %,d\n",{length(attractive(p)),p})end for`
Output:
```There are 74 attractive numbers up to and including 120:
{4,6,8,9,10,12,14,15,18,20,21,22,25,26,27,28,30,32,33,34,35,38,39,42,44,45,
46,48,49,50,51,52,55,57,58,62,63,65,66,68,69,70,72,74,75,76,77,78,80,82,85,
86,87,91,92,93,94,95,98,99,102,105,106,108,110,111,112,114,115,116,117,118,
119,120}
There are 636 attractive numbers up to 1,000
There are 6,396 attractive numbers up to 10,000
There are 63,255 attractive numbers up to 100,000
```

## Python

` # ver 2.7.12from sympy import sieve # library for primes def get_pfct(n): 	i = 2; factors = []	while i * i <= n:		if n % i:			i += 1		else:			n //= i			factors.append(i)	if n > 1:		factors.append(n)	return len(factors)  sieve.extend(110) # first 110 primes...primes=sieve._list pool=[] for each in xrange(0,121):	pool.append(get_pfct(each)) for i,each in enumerate(pool):	if each in primes:		print i,  `
Output:
```4,6,8,9,10,12,14,15,18,20,21,22,25,26,27,28,30,32,33,34,35,38,39,42,44,45,46, 48,49,50,51,52,55,57,58,62,63,65,66,68,69,70,72,74,75,76,77,78,80,82,85,86,87, 91,92,93,94,95,98,99,102,105,106,108,110,111,112,114,115,116,117,118,119,120
```

## Racket

`#lang racket(require math/number-theory)(define attractive? (compose1 prime? prime-omega))(filter attractive? (range 1 121))`
Output:
```(4 6 8 9 10 12 14 15 18 20 21 22 25 26 27 28 30 32 33 34 35 38 39 42 44 45 46 48 49 50 51 52 55 57 58 62 63 65 66 68 69 70 72 74 75 76 77 78 80 82 85 86 87 91 92 93 94 95 98 99 102 105 106 108 110 111 112 114 115 116 117 118 119 120)
```

## REXX

Programming notes: The use of a table that contains some low primes is one fast method to test for primality of the
various prime factors.

The   cFact   (count factors)   function   is optimized way beyond what this task requires,   and it can be optimized
further by expanding the     do whiles     clauses   (lines   3──►6   in the   cFact   function).

`/*REXX program finds and shows lists (or counts) attractive numbers up to a specified N.*/parse arg N .                                    /*get optional argument from the C.L.  */if N=='' | N==","  then N= 120                   /*Not specified?  Then use the default.*/cnt= N<0                                         /*semaphore used to control the output.*/N= abs(N)                                        /*ensure that  N  is a positive number.*/call genP 100                                    /*gen 100 primes (high= 541); overkill.*/sw= linesize()  -  1                             /*SW:    is the usable screen width.   */if \cnt  then say 'attractive numbers up to and including '        N        " are:"#= 0                                             /*number of attractive #'s  (so far).  */\$=                                               /*a list of attractive numbers (so far)*/    do j=1  for N;             a= cFact(j)       /*call cFact to count the factors in J.*/    if \@.a  then iterate                        /*if # of factors not prime, then skip.*/    #= # + 1                                     /*add  the index and number of factors.*/    if cnt   then iterate                        /*if not displaying numbers, skip list.*/    _= \$  j                                                 /*append a number to \$ list.*/    if length(_)>sw  then do;  say strip(\$);  \$= j;  end    /*display a line of numbers.*/                     else                     \$= _          /*append the latest number. */    end   /*j*/ if \$\==''  &  \cnt   then say strip(\$)           /*display any residual numbers in list.*/say;     say #     ' attractive numbers found up to and including '        Nexit                                             /*stick a fork in it,  we're all done. *//*──────────────────────────────────────────────────────────────────────────────────────*/cFact: procedure;  parse arg z 1 oz;  if z<2  then return z  /*if Z too small, return Z.*/       #= 0                                      /*#:  is the number of factors (so far)*/             do  while z//2==0;  #= #+1;  z= z%2;  end  /*maybe add the factor of two.  */             do  while z//3==0;  #= #+1;  z= z%3;  end  /*  "    "   "     "    " three.*/             do  while z//5==0;  #= #+1;  z= z%5;  end  /*  "    "   "     "    " five. */             do  while z//7==0;  #= #+1;  z= z%7;  end  /*  "    "   "     "    " seven.*/                                                 /* [↑]  reduce  Z  by some low primes. */          do k=11  by 6  while k<=z              /*insure that  K  isn't divisible by 3.*/          parse var k  ''  -1  _                 /*obtain the last decimal digit of  K. */          if _\==5  then do  while z//k==0;  #= #+1;   z= z%k;   end   /*maybe reduce Z.*/          if _ ==3  then iterate                 /*Next number ÷ by 5?  Skip.   ____    */          if k*k>oz then leave                   /*are we  greater  than the   √ OZ  ?  */          y= k + 2                               /*get next divisor,  hopefully a prime.*/                         do while  z//y==0;  #= #+1;   z= z%y;   end   /*maybe reduce Z.*/          end   /*k*/       if z\==1  then return # + 1               /*if residual isn't unity, then add it.*/                      return #                   /*return the number of factors in  OZ. *//*──────────────────────────────────────────────────────────────────────────────────────*/genP: procedure expose @.; parse arg n;           @.=0;         @.2= 1;     @.3= 1;   p= 2        do j=3  by 2  until p==n;   do k=3  by 2  until k*k>j;  if j//k==0  then iterate j                                    end  /*k*/;             @.j = 1;        p= p + 1        end   /*j*/;          return             /* [↑]  generate  N  primes.           */`

This REXX program makes use of   LINESIZE   REXX program (or BIF) which is used to determine the screen width (or linesize) of the terminal (console).
Some REXXes don't have this BIF.   It is used here to automatically/idiomatically limit the width of the output list.

The   LINESIZE.REX   REXX program is included here   ───►   LINESIZE.REX.

output   when using the default input:
```attractive numbers up to and including  120  are:
4 6 8 9 10 12 14 15 18 20 21 22 25 26 27 28 30 32 33 34 35 38 39 42 44 45 46 48 49 50 51 52 55 57 58 62 63 65 66 68 69 70 72 74
75 76 77 78 80 82 85 86 87 91 92 93 94 95 98 99 102 105 106 108 110 111 112 114 115 116 117 118 119 120

74  attractive numbers found up to and including  120
```
output   when using the input of:     -10000
```6396  attractive numbers found up to and including  10000
```

## Ring

` # Project: Attractive Numbers decomp = []nump = 0see "Attractive Numbers up to 120:" + nlwhile nump < 120decomp = []nump = nump + 1for i = 1 to nump    if isPrime(i) and nump%i = 0       add(decomp,i)       dec = nump/i       while dec%i = 0             add(decomp,i)             dec = dec/i       end    oknextif isPrime(len(decomp))    see string(nump) + " = ["for n = 1 to len(decomp)    if n < len(decomp)       see string(decomp[n]) + "*"    else       see string(decomp[n]) + "] - " + len(decomp) + " is prime" + nl    oknextokend  func isPrime(num)     if (num <= 1) return 0 ok     if (num % 2 = 0) and num != 2 return 0 ok     for i = 3 to floor(num / 2) -1 step 2         if (num % i = 0) return 0 ok     next     return 1 `
Output:
```Attractive Numbers up to 120:
4 = [2*2] - 2 is prime
6 = [2*3] - 2 is prime
8 = [2*2*2] - 3 is prime
9 = [3*3] - 2 is prime
10 = [2*5] - 2 is prime
12 = [2*2*3] - 3 is prime
14 = [2*7] - 2 is prime
15 = [3*5] - 2 is prime
18 = [2*3*3] - 3 is prime
20 = [2*2*5] - 3 is prime
...
...
...
102 = [2*3*17] - 3 is prime
105 = [3*5*7] - 3 is prime
106 = [2*53] - 2 is prime
108 = [2*2*3*3*3] - 5 is prime
110 = [2*5*11] - 3 is prime
111 = [3*37] - 2 is prime
112 = [2*2*2*2*7] - 5 is prime
114 = [2*3*19] - 3 is prime
115 = [5*23] - 2 is prime
116 = [2*2*29] - 3 is prime
117 = [3*3*13] - 3 is prime
118 = [2*59] - 2 is prime
119 = [7*17] - 2 is prime
120 = [2*2*2*3*5] - 5 is prime
```

## Ruby

`require "prime" p (1..120).select{|n| n.prime_division.sum(&:last).prime? } `
Output:
```[4, 6, 8, 9, 10, 12, 14, 15, 18, 20, 21, 22, 25, 26, 27, 28, 30, 32, 33, 34, 35, 38, 39, 42, 44, 45, 46, 48, 49, 50, 51, 52, 55, 57, 58, 62, 63, 65, 66, 68, 69, 70, 72, 74, 75, 76, 77, 78, 80, 82, 85, 86, 87, 91, 92, 93, 94, 95, 98, 99, 102, 105, 106, 108, 110, 111, 112, 114, 115, 116, 117, 118, 119, 120]
```

## Rust

Uses primal

`use primal::Primes; const MAX: u64 = 120; /// Returns an Option with a tuple => Ok((smaller prime factor, num divided by that prime factor))/// If num is a prime number itself, returns Nonefn extract_prime_factor(num: u64) -> Option<(u64, u64)> {    let mut i = 0;    if primal::is_prime(num) {        None    } else {        loop {            let prime = Primes::all().nth(i).unwrap() as u64;            if num % prime == 0 {                return Some((prime, num / prime));            } else {                i += 1;            }        }    }} /// Returns a vector containing all the prime factors of numfn factorize(num: u64) -> Vec<u64> {    let mut factorized = Vec::new();    let mut rest = num;    while let Some((prime, factorizable_rest)) = extract_prime_factor(rest) {        factorized.push(prime);        rest = factorizable_rest;    }    factorized.push(rest);    factorized} fn main() {    let mut output: Vec<u64> = Vec::new();    for num in 4 ..= MAX {        if primal::is_prime(factorize(num).len() as u64) {            output.push(num);        }    }    println!("The attractive numbers up to and including 120 are\n{:?}", output);}`
Output:
```The attractive numbers up to and including 120 are
[4, 6, 8, 9, 10, 12, 14, 15, 18, 20, 21, 22, 25, 26, 27, 28, 30, 32, 33, 34, 35, 38, 39, 42, 44, 45, 46, 48, 49, 50, 51, 52, 55, 57, 58, 62, 63, 65, 66, 68, 69, 70, 72, 74, 75, 76, 77, 78, 80, 82, 85, 86, 87, 91, 92, 93, 94, 95, 98, 99, 102, 105, 106, 108, 110, 111, 112, 114, 115, 116, 117, 118, 119, 120]```

## Scala

Output:
Best seen in running your browser either by ScalaFiddle (ES aka JavaScript, non JVM) or Scastie (remote JVM).
`object AttractiveNumbers extends App {  private val max = 120  private var count = 0   private def nFactors(n: Int): Int = {    @scala.annotation.tailrec    def factors(x: Int, f: Int, acc: Int): Int =      if (f * f > x) acc + 1      else        x % f match {          case 0 => factors(x / f, f, acc + 1)          case _ => factors(x, f + 1, acc)        }     factors(n, 2, 0)  }   private def ls: Seq[String] =    for (i <- 4 to max;         n = nFactors(i)         if n >= 2 && nFactors(n) == 1 // isPrime(n)         ) yield f"\$i%4d(\$n)"   println(f"The attractive numbers up to and including \$max%d are: [number(factors)]\n")  ls.zipWithIndex    .groupBy { case (_, index) => index / 20 }    .foreach { case (_, row) => println(row.map(_._1).mkString) }}`

## Sidef

`func is_attractive(n) {    n.bigomega.is_prime} 1..120 -> grep(is_attractive).say`
Output:
`[4, 6, 8, 9, 10, 12, 14, 15, 18, 20, 21, 22, 25, 26, 27, 28, 30, 32, 33, 34, 35, 38, 39, 42, 44, 45, 46, 48, 49, 50, 51, 52, 55, 57, 58, 62, 63, 65, 66, 68, 69, 70, 72, 74, 75, 76, 77, 78, 80, 82, 85, 86, 87, 91, 92, 93, 94, 95, 98, 99, 102, 105, 106, 108, 110, 111, 112, 114, 115, 116, 117, 118, 119, 120]`

## Visual Basic .NET

Translation of: D
`Module Module1    Const MAX = 120     Function IsPrime(n As Integer) As Boolean        If n < 2 Then Return False        If n Mod 2 = 0 Then Return n = 2        If n Mod 3 = 0 Then Return n = 3        Dim d = 5        While d * d <= n            If n Mod d = 0 Then Return False            d += 2            If n Mod d = 0 Then Return False            d += 4        End While        Return True    End Function     Function PrimefactorCount(n As Integer) As Integer        If n = 1 Then Return 0        If IsPrime(n) Then Return 1        Dim count = 0        Dim f = 2        While True            If n Mod f = 0 Then                count += 1                n /= f                If n = 1 Then Return count                If IsPrime(n) Then f = n            ElseIf f >= 3 Then                f += 2            Else                f = 3            End If        End While        Throw New Exception("Unexpected")    End Function     Sub Main()        Console.WriteLine("The attractive numbers up to and including {0} are:", MAX)        Dim i = 1        Dim count = 0        While i <= MAX            Dim n = PrimefactorCount(i)            If IsPrime(n) Then                Console.Write("{0,4}", i)                count += 1                If count Mod 20 = 0 Then                    Console.WriteLine()                End If            End If                i += 1        End While        Console.WriteLine()    End Sub End Module`
Output:
```The attractive numbers up to and including 120 are:
4   6   8   9  10  12  14  15  18  20  21  22  25  26  27  28  30  32  33  34
35  38  39  42  44  45  46  48  49  50  51  52  55  57  58  62  63  65  66  68
69  70  72  74  75  76  77  78  80  82  85  86  87  91  92  93  94  95  98  99
102 105 106 108 110 111 112 114 115 116 117 118 119 120```

## zkl

Using GMP (GNU Multiple Precision Arithmetic Library, probabilistic primes) because it is easy and fast to test for primeness.

`var [const] BI=Import("zklBigNum");  // libGMPfcn attractiveNumber(n){ BI(primeFactors(n).len()).probablyPrime() } println("The attractive numbers up to and including 120 are:");[1..120].filter(attractiveNumber)   .apply("%4d".fmt).pump(Void,T(Void.Read,19,False),"println");`
`fcn primeFactors(n){  // Return a list of factors of n   acc:=fcn(n,k,acc,maxD){  // k is 2,3,5,7,9,... not optimum      if(n==1 or k>maxD) acc.close();      else{	 q,r:=n.divr(k);   // divr-->(quotient,remainder)	 if(r==0) return(self.fcn(q,k,acc.write(k),q.toFloat().sqrt()));	 return(self.fcn(n,k+1+k.isOdd,acc,maxD))      }   }(n,2,Sink(List),n.toFloat().sqrt());   m:=acc.reduce('*,1);      // mulitply factors   if(n!=m) acc.append(n/m); // opps, missed last factor   else acc;}`
Output:
```The attractive numbers up to and including 120 are:
4   6   8   9  10  12  14  15  18  20  21  22  25  26  27  28  30  32  33  34
35  38  39  42  44  45  46  48  49  50  51  52  55  57  58  62  63  65  66  68
69  70  72  74  75  76  77  78  80  82  85  86  87  91  92  93  94  95  98  99
102 105 106 108 110 111 112 114 115 116 117 118 119 120
```