cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A375471 Integers equal to the sum of divisors of their anti-divisors.

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%I A375471 #20 Jul 04 2025 15:33:38
%S A375471 3,4,16,61,1861,4979,90191,58981439,10024953661
%N A375471 Integers equal to the sum of divisors of their anti-divisors.
%C A375471 Tested up to 2*10^10. - _Giovanni Resta_, Aug 19 2024
%e A375471 Anti-divisors of 1861 are 2, 3, 17, 51, 61, 73, 219, 1241 and
%e A375471 sum of sigmas = 3 + 4 + 18 + 72 + 62 + 74 + 296 + 1332 = 1861.
%Y A375471 Cf. A000203, A066417, A178029.
%K A375471 nonn,hard,more
%O A375471 1,1
%A A375471 _Paolo P. Lava_, Aug 17 2024
%E A375471 a(8)-a(9) from _Giovanni Resta_, Aug 19 2024