- #!/usr/bin/perl
- # Pisano Periods 1
- # https://projecteuler.net/problem=853
- # Runtime: 1.017s
- use 5.036;
- use Math::Sidef qw(fibonacci pisano_period sum divisors);
- my $n = 120;
- my $limit = 1e9;
- say sum(grep { pisano_period($_) == $n } divisors(fibonacci($n), $limit));
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