Square but not cube

From Rosetta Code
Task
Square but not cube
You are encouraged to solve this task according to the task description, using any language you may know.
Task

Show the first 30 positive integers which are squares but not cubes of such integers.

Optionally, show also the first 3 positive integers which are both squares and cubes - and mark them as such.

ALGOL 68[edit]

Avoids computing cube roots.

BEGIN
# list the first 30 numbers that are squares but not cubes and also #
# show the numbers that are both squares and cubes #
INT count := 0;
INT c := 1;
INT c3 := 1;
FOR s WHILE count < 30 DO
INT sq = s * s;
WHILE c3 < sq DO
c +:= 1;
c3 := c * c * c
OD;
print( ( whole( sq, -5 ) ) );
IF c3 = sq THEN
# the square is also a cube #
print( ( " is also the cube of ", whole( c, -5 ) ) )
ELSE
# square only #
count +:= 1
FI;
print( ( newline ) )
OD
END
Output:
    1 is also the cube of     1
    4
    9
   16
   25
   36
   49
   64 is also the cube of     4
   81
  100
  121
  144
  169
  196
  225
  256
  289
  324
  361
  400
  441
  484
  529
  576
  625
  676
  729 is also the cube of     9
  784
  841
  900
  961
 1024
 1089

AppleScript[edit]

on run
script listing
on |λ|(x)
set sqr to x * x
set strSquare to sqr as text
 
if isCube(sqr) then
strSquare & " (also cube)"
else
strSquare
end if
end |λ|
end script
 
unlines(map(listing, ¬
enumFromTo(1, 33)))
end run
 
-- isCube :: Int -> Bool
on isCube(x)
x = (round (x ^ (1 / 3))) ^ 3
end isCube
 
 
-- GENERIC FUNCTIONS -------------------------------------------------
 
-- enumFromTo :: Int -> Int -> [Int]
on enumFromTo(m, n)
if m ≤ n then
set lst to {}
repeat with i from m to n
set end of lst to i
end repeat
return lst
else
return {}
end if
end enumFromTo
 
-- map :: (a -> b) -> [a] -> [b]
on map(f, xs)
tell mReturn(f)
set lng to length of xs
set lst to {}
repeat with i from 1 to lng
set end of lst to |λ|(item i of xs, i, xs)
end repeat
return lst
end tell
end map
 
-- Lift 2nd class handler function into 1st class script wrapper
-- mReturn :: First-class m => (a -> b) -> m (a -> b)
on mReturn(f)
if class of f is script then
f
else
script
property |λ| : f
end script
end if
end mReturn
 
-- unlines :: [String] -> String
on unlines(xs)
set {dlm, my text item delimiters} to ¬
{my text item delimiters, linefeed}
set str to xs as text
set my text item delimiters to dlm
str
end unlines
Output:
1 (also cube)
4
9
16
25
36
49
64 (also cube)
81
100
121
144
169
196
225
256
289
324
361
400
441
484
529
576
625
676
729 (also cube)
784
841
900
961
1024
1089

AWK[edit]

 
# syntax: GAWK -f SQUARE_BUT_NOT_CUBE.AWK
BEGIN {
while (n < 30) {
sqpow = ++square ^ 2
if (is_cube(sqpow) == 0) {
n++
printf("%4d\n",sqpow)
}
else {
printf("%4d is square and cube\n",sqpow)
}
}
exit(0)
}
function is_cube(x, i) {
for (i=1; i<=x; i++) {
if (i ^ 3 == x) {
return(1)
}
}
return(0)
}
 
Output:
   1 is square and cube
   4
   9
  16
  25
  36
  49
  64 is square and cube
  81
 100
 121
 144
 169
 196
 225
 256
 289
 324
 361
 400
 441
 484
 529
 576
 625
 676
 729 is square and cube
 784
 841
 900
 961
1024
1089

C[edit]

#include <stdio.h>
#include <math.h>
 
int main() {
int n = 1, count = 0, sq, cr;
for ( ; count < 30; ++n) {
sq = n * n;
cr = (int)cbrt((double)sq);
if (cr * cr * cr != sq) {
count++;
printf("%d\n", sq);
}
else {
printf("%d is square and cube\n", sq);
}
}
return 0;
}
Output:
Same as Ring example.

F#[edit]

 
let rec fN n g φ=if φ<31 then match compare(n*n)(g*g*g) with | -1->printfn "%d"(n*n);fN(n+1) g (φ+1)
| 0->printfn "%d cube and square"(n*n);fN(n+1)(g+1)φ
| 1->fN n (g+1) φ
fN 1 1 1
 
Output:
1 cube and square
4
9
16
25
36
49
64 cube and square
81
100
121
144
169
196
225
256
289
324
361
400
441
484
529
576
625
676
729 cube and square
784
841
900
961
1024
1089

Factor[edit]

Translation of: F#
USING: combinators interpolate io kernel prettyprint math
math.functions math.order pair-rocket ;
IN: rosetta-code.square-but-not-cube
 
: fn ( s c n -- s' c' n' )
dup 31 < [
2over [ sq ] [ 3 ^ ] bi* <=> {
+lt+ => [ [ dup sq . 1 + ] 2dip 1 + fn ]
+eq+ => [ [ dup sq [I ${} cube and squareI] nl 1 + ] [ 1 + ] [ ] tri* fn ]
+gt+ => [ [ 1 + ] dip fn ]
} case
] when ;
 
1 1 1 fn 3drop
Output:
1 cube and square
4
9
16
25
36
49
64 cube and square
81
100
121
144
169
196
225
256
289
324
361
400
441
484
529
576
625
676
729 cube and square
784
841
900
961
1024
1089

Go[edit]

package main
 
import (
"fmt"
"math"
)
 
func main() {
for n, count := 1, 0; count < 30; n++ {
sq := n * n
cr := int(math.Cbrt(float64(sq)))
if cr*cr*cr != sq {
count++
fmt.Println(sq)
} else {
fmt.Println(sq, "is square and cube")
}
}
}
Output:
1 is square and cube
4
9
16
25
36
49
64 is square and cube
81
100
121
144
169
196
225
256
289
324
361
400
441
484
529
576
625
676
729 is square and cube
784
841
900
961
1024
1089

Haskell[edit]

import Data.List (partition, sortBy)
import Control.Monad (join)
import Data.Ord (comparing)
 
isCube :: Int -> Bool
isCube n = n == round (fromIntegral n ** (1 / 3)) ^ 3
 
both, only :: [Int]
(both, only) = partition isCube $ join (*) <$> [1 ..]
 
-- TEST -----------------------------------------------------------
main :: IO ()
main =
(putStrLn . unlines) $
uncurry ((++) . show) <$>
sortBy
(comparing fst)
((flip (,) " (also cube)" <$> take 3 both) ++ (flip (,) "" <$> take 30 only))

Or simply

import Control.Monad (join)
 
cubeRoot :: Int -> Int
cubeRoot = round . (** (1 / 3)) . fromIntegral
 
isCube :: Int -> Bool
isCube = (==) <*> ((^ 3) . cubeRoot)
 
-- TEST ---------------------------------------------
main :: IO ()
main =
(putStrLn . unlines) $
(\x ->
show x ++
if isCube x
then concat [" (also cube of ", show (cubeRoot x), ")"]
else []) <$>
take 33 (join (*) <$> [1 ..])

Or, if we prefer a finite series to an infinite one

import Control.Applicative (liftA2)
 
isCube :: Int -> Bool
isCube = (==) <*> ((^ 3) . round . (** (1 / 3)) . fromIntegral)
 
squares :: Int -> Int -> [Int]
squares m n = (>>= id) (*) <$> [m .. n]
 
-- TEST ------------------------------------------------------------
main :: IO ()
main = (putStrLn . unlines) $ liftA2 (++) show label <$> squares 1 33
 
label :: Int -> String
label n
| isCube n = " (also cube)"
| otherwise = ""
Output:
1 (also cube)
4
9
16
25
36
49
64 (also cube)
81
100
121
144
169
196
225
256
289
324
361
400
441
484
529
576
625
676
729 (also cube)
784
841
900
961
1024
1089

IS-BASIC[edit]

100 PROGRAM "Square.bas"
110 LET SQNOTCB,SQANDCB,SQNUM,CBNUM,CBN,SQN,D1=0:LET SQD,D2=1
120 DO
130 LET SQN=SQN+1:LET SQNUM=SQNUM+SQD:LET SQD=SQD+2
140 IF SQNUM>CBNUM THEN
150 LET CBN=CBN+1:LET CBNUM=CBNUM+D2
160 LET D1=D1+6:LET D2=D2+D1
170 END IF
180 IF SQNUM<>CBNUM THEN
190 PRINT SQNUM:LET SQNOTCB=SQNOTCB+1
200 ELSE
210 PRINT SQNUM,SQN;"*";SQN;"=";CBN;"*";CBN;"*";CBN
220 LET SQANDCB=SQANDCB+1
230 END IF
240 LOOP UNTIL SQNOTCB>=30
250 PRINT SQANDCB;"where numbers are square and cube."

JavaScript[edit]

(() => {
'use strict';
 
const main = () =>
unlines(map(
x => x.toString() + (
isCube(x) ? (
` (cube of ${cubeRootInt(x)} and square of ${
Math.pow(x, 1/2)
})`
) : ''
),
map(x => x * x, enumFromTo(1, 33))
));
 
// isCube :: Int -> Bool
const isCube = n =>
n === Math.pow(cubeRootInt(n), 3);
 
// cubeRootInt :: Int -> Int
const cubeRootInt = n => Math.round(Math.pow(n, 1 / 3));
 
 
// GENERIC FUNCTIONS ----------------------------------
 
// enumFromTo :: Int -> Int -> [Int]
const enumFromTo = (m, n) =>
m <= n ? iterateUntil(
x => n <= x,
x => 1 + x,
m
) : [];
 
// iterateUntil :: (a -> Bool) -> (a -> a) -> a -> [a]
const iterateUntil = (p, f, x) => {
const vs = [x];
let h = x;
while (!p(h))(h = f(h), vs.push(h));
return vs;
};
 
// map :: (a -> b) -> [a] -> [b]
const map = (f, xs) => xs.map(f);
 
// unlines :: [String] -> String
const unlines = xs => xs.join('\n');
 
// MAIN ---
return main();
})();
Output:
1 (cube of 1 and square of 1)
4
9
16
25
36
49
64 (cube of 4 and square of 8)
81
100
121
144
169
196
225
256
289
324
361
400
441
484
529
576
625
676
729 (cube of 9 and square of 27)
784
841
900
961
1024
1089

Julia[edit]

 
iscube(n) = n == round(Int, cbrt(n))^3
 
println(collect(Iterators.take((n^2 for n in 1:10^6 if !iscube(n^2)), 30)))
 
Output:

[4, 9, 16, 25, 36, 49, 81, 100, 121, 144, 169, 196, 225, 256, 289, 324, 361, 400, 441, 484, 529, 576, 625, 676, 784, 841, 900, 961, 1024, 1089]

Kotlin[edit]

// Version 1.2.60
 
fun main(args: Array<String>) {
var n = 1
var count = 0
while (count < 30) {
val sq = n * n
val cr = Math.cbrt(sq.toDouble()).toInt()
if (cr * cr * cr != sq) {
count++
println(sq)
}
else {
println("$sq is square and cube")
}
n++
}
}
Output:
Same as Ring example.

Pascal[edit]

Only using addition :-)

program SquareButNotCube;
var
sqN,
sqDelta,
SqNum,
 
cbN,
cbDelta1,
cbDelta2,
CbNum,
 
CountSqNotCb,
CountSqAndCb : NativeUint;
 
begin
CountSqNotCb := 0;
CountSqAndCb := 0;
SqNum := 0;
CbNum := 0;
cbN := 0;
sqN := 0;
sqDelta := 1;
cbDelta1 := 0;
cbDelta2 := 1;
repeat
inc(sqN);
inc(sqNum,sqDelta);
inc(sqDelta,2);
IF sqNum>cbNum then
Begin
inc(cbN);
cbNum := cbNum+cbDelta2;
inc(cbDelta1,6);// 0,6,12,18...
inc(cbDelta2,cbDelta1);//1,7,19,35...
end;
IF sqNum <> cbNUm then
Begin
writeln(sqNum :25);
inc(CountSqNotCb);
end
else
Begin
writeln(sqNum:25,sqN:10,'*',sqN,' = ',cbN,'*',cbN,'*',cbN);
inc(CountSqANDCb);
end;
until CountSqNotCb >= 30;//sqrt(High(NativeUint));
writeln(CountSqANDCb,' where numbers are square and cube ');
end.
Output:
                        1         1*1 = 1*1*1
                        4
                        9
                       16
                       25
                       36
                       49
                       64         8*8 = 4*4*4
                       81
                      100
                      121
                      144
                      169
                      196
                      225
                      256
                      289
                      324
                      361
                      400
                      441
                      484
                      529
                      576
                      625
                      676
                      729        27*27 = 9*9*9
                      784
                      841
                      900
                      961
                     1024
                     1089
3 where numbers are square and cube

// there are 1625 numbers which are square and cube < High(Uint64)     
//18412815093994140625  4291015625*4291015625 = 2640625*2640625*2640625

Perl[edit]

Hash[edit]

Use a hash to track state (and avoid floating-point math).

while ($cnt < 30) {
$n++;
$h{$n**2}++;
$h{$n**3}--;
$cnt++ if $h{$n**2} > 0;
}
 
print "First 30 positive integers that are a square but not a cube:\n";
print "$_ " for sort { $a <=> $b } grep { $h{$_} == 1 } keys %h;
 
print "\n\nFirst 3 positive integers that are both a square and a cube:\n";
print "$_ " for sort { $a <=> $b } grep { $h{$_} == 0 } keys %h;
Output:
First 30 positive integers that are a square but not a cube:
4 9 16 25 36 49 81 100 121 144 169 196 225 256 289 324 361 400 441 484 529 576 625 676 784 841 900 961 1024 1089

First 3 positive integers that are both a square and a cube:
1 64 729

Generators[edit]

A more general approach involving generators/closures to implement 'lazy' lists as in the Perl 6 example. Using ideas and code from the very similar Generator exponential task. Output is the same as previous.

# return an anonymous subroutine that generates stream of specified powers
sub gen_pow {
my $m = shift;
my $e = 1;
return sub { return $e++ ** $m; };
}
 
# return an anonymous subroutine generator that filters output from supplied generators g1 and g2
sub gen_filter {
my($g1, $g2) = @_;
my $v1;
my $v2 = $g2->();
return sub {
while (1) {
$v1 = $g1->();
$v2 = $g2->() while $v1 > $v2;
return $v1 unless $v1 == $v2;
}
};
}
 
my $pow2 = gen_pow(2);
my $pow3 = gen_pow(3);
my $squares_without_cubes = gen_filter($pow2, $pow3);
print "First 30 positive integers that are a square but not a cube:\n";
print $squares_without_cubes->() . ' ' for 1..30;
 
my $pow6 = gen_pow(6);
print "\n\nFirst 3 positive integers that are both a square and a cube:\n";
print $pow6->() . ' ' for 1..3;

Perl 6[edit]

my @square-and-cube = map { .}, 1..Inf;
 
my @square-but-not-cube = (1..Inf).map({ .² }).grep({ $_@square-and-cube[^@square-and-cube.first: * > $_, :k]});
 
put "First 30 positive integers that are a square but not a cube: \n", @square-but-not-cube[^30];
 
put "\nFirst 15 positive integers that are both a square and a cube: \n", @square-and-cube[^15];
Output:
First 30 positive integers that are a square but not a cube: 
4 9 16 25 36 49 81 100 121 144 169 196 225 256 289 324 361 400 441 484 529 576 625 676 784 841 900 961 1024 1089

First 15 positive integers that are both a square and a cube: 
1 64 729 4096 15625 46656 117649 262144 531441 1000000 1771561 2985984 4826809 7529536 11390625

Python[edit]

# nonCubeSquares :: Int -> [(Int, Bool)]
def nonCubeSquares(n):
upto = enumFromTo(1)
ns = upto(n)
setCubes = set(x ** 3 for x in ns)
ms = upto(n + len(set(x * x for x in ns).intersection(
setCubes
)))
return list(tuple([x * x, x in setCubes]) for x in ms)
 
 
# squareListing :: [(Int, Bool)] -> [String]
def squareListing(xs):
justifyIdx = justifyRight(len(str(1 + len(xs))))(' ')
justifySqr = justifyRight(1 + len(str(xs[-1][0])))(' ')
return list(
'(' + str(1 + idx) + '^2 = ' + str(n) +
' = ' + str(round(n ** (1 / 3))) + '^3)' if bln else (
justifyIdx(1 + idx) + ' ->' +
justifySqr(n)
)
for idx, (n, bln) in enumerate(xs)
)
 
 
def main():
print(
unlines(
squareListing(
nonCubeSquares(30)
)
)
)
 
 
# GENERIC ------------------------------------------------------------------
 
# enumFromTo :: Int -> Int -> [Int]
def enumFromTo(m):
return lambda n: list(range(m, 1 + n))
 
 
# justifyRight :: Int -> Char -> String -> String
def justifyRight(n):
return lambda cFiller: lambda a: (
((n * cFiller) + str(a))[-n:]
)
 
 
# unlines :: [String] -> String
def unlines(xs):
return '\n'.join(xs)
 
 
main()
Output:
(1^2 = 1 = 1^3)
 2 ->    4
 3 ->    9
 4 ->   16
 5 ->   25
 6 ->   36
 7 ->   49
(8^2 = 64 = 4^3)
 9 ->   81
10 ->  100
11 ->  121
12 ->  144
13 ->  169
14 ->  196
15 ->  225
16 ->  256
17 ->  289
18 ->  324
19 ->  361
20 ->  400
21 ->  441
22 ->  484
23 ->  529
24 ->  576
25 ->  625
26 ->  676
(27^2 = 729 = 9^3)
28 ->  784
29 ->  841
30 ->  900
31 ->  961
32 -> 1024
33 -> 1089

REXX[edit]

Programming note:   extra code was added to support an additional output format   (see the 2nd output section).

/*REXX pgm shows N ints>0 that are squares and not cubes, & which are squares and cubes.*/
numeric digits 20 /*be able to handle some large numbers.*/
parse arg N . /*obtain optional argument from the CL.*/
if N=='' | N=="," then N=30 /*Not specified? Then use the default.*/
sqcb= N<0 /*N negative? Then show squares & cubes*/
N = abs(N) /*define N to be the absolute value. */
w= length(N) + 3 /*W: used for aligning output columns.*/
say ' count ' /*display the 1st line of the title. */
say ' ─────── ' /* " " 2nd " " " " */
@.= 0 /*@: stemmed array for computed cubes.*/
#= 0; ##= 0 /*count (integer): squares & not cubes.*/
do j=1 until #==N | ##==N /*loop 'til enough " " " " */
sq= j*j; cube= sq*j; @.cube= 1 /*compute the square of J and the cube.*/
if @.sq then do
##= ## + 1 /*bump the counter of squares and cubs.*/
if \sqcb then counter= left('', 12) /*don't show this counter.*/
else counter= center(##, 12) /* do " " " */
say counter right(sq, 3*w) 'is a square and a cube'
end
else do
if sqcb then iterate
#= # + 1 /*bump the counter of squares & ¬ cubes*/
say center(#, 12) right(sq, 3*w) 'is a square and not a cube'
end
end /*j*/ /*stick a fork in it, we're all done. */
output   when using the default input:
   count
  ───────
                           1 is a square and       a cube
     1                     4 is a square and  not  a cube
     2                     9 is a square and  not  a cube
     3                    16 is a square and  not  a cube
     4                    25 is a square and  not  a cube
     5                    36 is a square and  not  a cube
     6                    49 is a square and  not  a cube
                          64 is a square and       a cube
     7                    81 is a square and  not  a cube
     8                   100 is a square and  not  a cube
     9                   121 is a square and  not  a cube
     10                  144 is a square and  not  a cube
     11                  169 is a square and  not  a cube
     12                  196 is a square and  not  a cube
     13                  225 is a square and  not  a cube
     14                  256 is a square and  not  a cube
     15                  289 is a square and  not  a cube
     16                  324 is a square and  not  a cube
     17                  361 is a square and  not  a cube
     18                  400 is a square and  not  a cube
     19                  441 is a square and  not  a cube
     20                  484 is a square and  not  a cube
     21                  529 is a square and  not  a cube
     22                  576 is a square and  not  a cube
     23                  625 is a square and  not  a cube
     24                  676 is a square and  not  a cube
                         729 is a square and       a cube
     25                  784 is a square and  not  a cube
     26                  841 is a square and  not  a cube
     27                  900 is a square and  not  a cube
     28                  961 is a square and  not  a cube
     29                 1024 is a square and  not  a cube
     30                 1089 is a square and  not  a cube
output   when using the input of:     -55
   count
  ───────
     1                     1 is a square and       a cube
     2                    64 is a square and       a cube
     3                   729 is a square and       a cube
     4                  4096 is a square and       a cube
     5                 15625 is a square and       a cube
     6                 46656 is a square and       a cube
     7                117649 is a square and       a cube
     8                262144 is a square and       a cube
     9                531441 is a square and       a cube
     10              1000000 is a square and       a cube
     11              1771561 is a square and       a cube
     12              2985984 is a square and       a cube
     13              4826809 is a square and       a cube
     14              7529536 is a square and       a cube
     15             11390625 is a square and       a cube
     16             16777216 is a square and       a cube
     17             24137569 is a square and       a cube
     18             34012224 is a square and       a cube
     19             47045881 is a square and       a cube
     20             64000000 is a square and       a cube
     21             85766121 is a square and       a cube
     22            113379904 is a square and       a cube
     23            148035889 is a square and       a cube
     24            191102976 is a square and       a cube
     25            244140625 is a square and       a cube
     26            308915776 is a square and       a cube
     27            387420489 is a square and       a cube
     28            481890304 is a square and       a cube
     29            594823321 is a square and       a cube
     30            729000000 is a square and       a cube
     31            887503681 is a square and       a cube
     32           1073741824 is a square and       a cube
     33           1291467969 is a square and       a cube
     34           1544804416 is a square and       a cube
     35           1838265625 is a square and       a cube
     36           2176782336 is a square and       a cube
     37           2565726409 is a square and       a cube
     38           3010936384 is a square and       a cube
     39           3518743761 is a square and       a cube
     40           4096000000 is a square and       a cube
     41           4750104241 is a square and       a cube
     42           5489031744 is a square and       a cube
     43           6321363049 is a square and       a cube
     44           7256313856 is a square and       a cube
     45           8303765625 is a square and       a cube
     46           9474296896 is a square and       a cube
     47          10779215329 is a square and       a cube
     48          12230590464 is a square and       a cube
     49          13841287201 is a square and       a cube
     50          15625000000 is a square and       a cube
     51          17596287801 is a square and       a cube
     52          19770609664 is a square and       a cube
     53          22164361129 is a square and       a cube
     54          24794911296 is a square and       a cube
     55          27680640625 is a square and       a cube

Ring[edit]

 
# Project : Square but not cube
 
limit = 30
num = 0
sq = 0
while num < limit
sq = sq + 1
sqpow = pow(sq,2)
flag = iscube(sqpow)
if flag = 0
num = num + 1
see sqpow + nl
else
see "" + sqpow + " is square and cube" + nl
ok
end
 
func iscube(cube)
for n = 1 to cube
if pow(n,3) = cube
return 1
ok
next
return 0
 

Output:

1 is square and cube
4
9
16
25
36
49
64 is square and cube
81
100
121
144
169
196
225
256
289
324
361
400
441
484
529
576
625
676
729 is square and cube
784
841
900
961
1024
1089

Ruby[edit]

#!/usr/bin/env ruby
 
class PowIt
:next
 
def initialize
@next = 1;
end
end
 
class SquareIt < PowIt
def next
result = @next ** 2
@next += 1
return result
end
end
 
class CubeIt < PowIt
def next
result = @next ** 3
@next += 1
return result
end
end
 
squares = []
hexponents = []
 
squit = SquareIt.new
cuit = CubeIt.new
 
s = squit.next
c = cuit.next
 
while (squares.length < 30 || hexponents.length < 3)
if s < c
squares.push(s) if squares.length < 30
s = squit.next
elsif s == c
hexponents.push(s) if hexponents.length < 3
s = squit.next
c = cuit.next
else
c = cuit.next
end
end
 
puts "Squares:"
puts squares.join(" ")
 
puts "Square-and-cubes:"
puts hexponents.join(" ")
Output:
Squares:
4 9 16 25 36 49 81 100 121 144 169 196 225 256 289 324 361 400 441 484 529 576 625 676 784 841 900 961 1024 1089
Square-and-cubes:
1 64 729

Sidef[edit]

Translation of: Perl 6
var square_and_cube = Enumerator({|f|
1..Inf -> each {|n| f(n**6) }
})
 
var square_but_not_cube = Enumerator({|f|
1..Inf -> lazy.map {|n| n**2 }.grep {|n| !n.is_power(3) }.each {|n| f(n) }
})
 
say "First 30 positive integers that are a square but not a cube:"
say square_but_not_cube.first(30).join(' ')
 
say "First 15 positive integers that are both a square and a cube:"
say square_and_cube.first(15).join(' ')
Output:
First 30 positive integers that are a square but not a cube:
4 9 16 25 36 49 81 100 121 144 169 196 225 256 289 324 361 400 441 484 529 576 625 676 784 841 900 961 1024 1089
First 15 positive integers that are both a square and a cube:
1 64 729 4096 15625 46656 117649 262144 531441 1000000 1771561 2985984 4826809 7529536 11390625

zkl[edit]

println("First 30 positive integers that are a square but not a cube:");
squareButNotCube:=(1).walker(*).tweak(fcn(n){
sq,cr := n*n, sq.toFloat().pow(1.0/3).round(); // cube root(64)<4
if(sq==cr*cr*cr) Void.Skip else sq
});
squareButNotCube.walk(30).concat(",").println("\n");
 
println("First 15 positive integers that are both a square and a cube:");
println((1).walker(*).tweak((1).pow.unbind().fp1(6)).walk(15));
Output:
First 30 positive integers that are a square but not a cube:
4,9,16,25,36,49,81,100,121,144,169,196,225,256,289,324,361,400,441,484,529,576,625,676,784,841,900,961,1024,1089

First 15 positive integers that are both a square and a cube:
L(1,64,729,4096,15625,46656,117649,262144,531441,1000000,1771561,2985984,4826809,7529536,11390625