#!/usr/bin/env perl
use warnings;
use strict;
use Math::Prime::Util qw/:all/;
my $sum = 0;
foreach my $a (1..10000) {
my $b = divisor_sum($a)-$a;
$sum += $a + $b if $b > $a && $a == divisor_sum($b)-$b;
}
print "$sum\n";
#!/usr/bin/env perl
use warnings;
use strict;
use Math::Prime::Util qw/:all/;
my $sum = 0;
foreach my $a (1..10000) {
my $b = divisor_sum($a)-$a;
$sum += $a + $b if $b > $a && $a == divisor_sum($b)-$b;
}
print "$sum\n";