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- #!/usr/bin/perl
- # Composite numbers that divide the reverse of the concatenation of their ascending order prime factors, with repetition.
- # https://oeis.org/A371696
- # Known terms:
- # 26, 38, 46, 378, 26579, 84941, 178838, 30791466, 39373022, 56405502, 227501395, 904085931
- # New terms:
- # 1657827142
- use 5.036;
- use ntheory qw(:all);
- # Next term is greater than:
- my $from = 11062000000;
- forfactored {
- if ($_ % 1e6 == 0) {
- say "Testing: $_";
- }
- if (@_ > 1 and modint(scalar reverse(join('', @_)), $_) == 0) {
- die "Found new term: $_\n";
- }
- } $from, 1e12;
- __END__
- Testing: 1656000000
- Testing: 1657000000
- Found new term: 1657827142
- perl prog.pl 585.29s user 0.29s system 99% cpu 9:49.90 total
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