Juggler sequence

editable example

Click the pencil to open this in an editor, change it, and run it in your browser. The same solution is posted on Rosetta Code.

ghul

use IO.Std.write_line

use System.Math.sqrt

step(value: long) -> long =>

if (value % 2L) == 0L then

cast long(sqrt(cast double(value)))

else

cast long(cast double(value) * sqrt(cast double(value)))

fi

stats(start: long) -> (int, long, int) => (

let current mut = start

let terms mut = 0

let highest mut = start

let at mut = 0

while current != 1L do

current = step(current)

terms = terms + 1

if current > highest then

highest = current

at = terms

fi

od

(terms, highest, at)

)

write_line(" n l h i")

for n in 20::39 do

let (terms, highest, at) = stats(cast long(n))

write_line("{n,3} {terms,3} {highest,17:N0} {at}")

od

  n   l                h  i
 20    3                 20  0
 21    9                140  4
 22    3                 22  0
 23    9                110  1
 24    3                 24  0
 25   11             52,214  3
 26    6                 36  3
 27    6                140  1
 28    6                 36  3
 29    9                156  1
 30    6                 36  3
 31    6                172  1
 32    6                 36  3
 33    8              2,598  2
 34    6                 36  3
 35    8              2,978  2
 36    3                 36  0
 37   17  24,906,114,455,136  8
 38    3                 38  0
 39   14            233,046  3