Select Code to Download

use strict;
use warnings;
...

say {*STDERR} time - $t;

use strict;
use warnings;
...

say {*STDERR} time - $t;

1e7:
    serial    15.311s   1 core
...
Collatz(46564287) has sequence length of 735 steps
Collatz(69846431) has sequence length of 733 steps