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-rwxr-xr-x | 046.pl | 19 |
1 files changed, 19 insertions, 0 deletions
@@ -0,0 +1,19 @@ +#!/usr/bin/perl +use strict; +use warnings; +use Math::Prime::XS qw/sieve_primes/; +use integer; + +my @primes = sieve_primes(1e6); +my %primes = map { $_, 1 } @primes; + +N: for my $n (2..100000) { + my $oddn = $n * 2 - 1; + next if exists $primes{$oddn}; + for my $m (1..sqrt($oddn)) { + my $possible_prime = $oddn - 2 * $m**2; + next N if $primes{$possible_prime}; + } + print "$oddn\n"; + last; +} |