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.
%I A274560 #24 Jun 10 2025 16:58:18 %S A274560 3,5,6,8,10,11,15,27,34,72,232,34432,549762629632 %N A274560 Numbers k such that sigma(k) == 0 (mod k-7). %e A274560 sigma(8) mod (8-7) = 15 mod 1 = 0. %t A274560 Select[Range[1, 10^6], Mod[DivisorSigma[1, #], # - 7] == 0 &] (* _Michael De Vlieger_, Jul 05 2016 *) %Y A274560 Contains subsequence A141550. %Y A274560 Cf. A000203, A045770, A067702, A088833, A181598, A274551, A274552, A274553, A274554, A274556, A274557, A274558, A274559, A274561, A274562, A274563, A274564, A274565, A274566 %K A274560 nonn,more %O A274560 1,1 %A A274560 _Paolo P. Lava_, Jul 05 2016 %E A274560 a(13) from _Giovanni Resta_ %E A274560 Terms 3,5,6 inserted by _Max Alekseyev_, May 29 2025