Perfect numbers: Difference between revisions

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Thundergnat (talk | contribs)
→‎{{header|Perl 6}}: Add a much faster variation
Thundergnat (talk | contribs)
m →‎{{header|Perl 6}}: Actually filter for primes. Wasn't wrong, just slower
Line 2,137: Line 2,137:
<pre>6 28 496 8128</pre>
<pre>6 28 496 8128</pre>
Much, much faster version:
Much, much faster version:
<lang perl6>my @primes = lazy 2,3,*+2 … Inf;
<lang perl6>my @primes = lazy (2,3,*+2 … Inf).grep: { .is-prime };
my @perfects = lazy gather for @primes {
my @perfects = lazy gather for @primes {
my $n = 2**$_ - 1;
my $n = 2**$_ - 1;