14 lines
404 B
Perl
14 lines
404 B
Perl
use v5.36;
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use ntheory <is_prime factorial>;
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sub show ($d) { my $l = length $d; $l < 41 ? $d : substr($d,0,20) . '..' . substr($d,-20) . " ($l digits)" }
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my($cnt,$n);
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my $fmt = "%2d: %3d! %s 1 = %s\n";
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while () {
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my $f = factorial ++$n;
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if (is_prime $f-1) { printf $fmt, ++$cnt, $n, '-', show $f-1 }
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if (is_prime $f+1) { printf $fmt, ++$cnt, $n, '+', show $f+1 }
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last if $cnt == 30;
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}
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