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 A274563 #21 Jun 09 2025 10:27:40 %S A274563 15,208,6976,8415,31815,351351,2077696,20487159,159030135,536559616, %T A274563 2586415095,137433972736,2199003332608 %N A274563 Numbers k such that sigma(k) == 0 (mod k+9). %e A274563 sigma(15) mod (15 + 9) = 24 mod 24 = 0. %t A274563 Select[Range[10^6], Mod[DivisorSigma[1, #], # + 9] == 0 &] (* _Michael De Vlieger_, Jul 06 2016 *) %Y A274563 Cf. A045770, A067702, A088833, A181598, A223610, A274551-A274562, A274564-A274566. %K A274563 nonn,more %O A274563 1,1 %A A274563 _Paolo P. Lava_, Jul 06 2016 %E A274563 a(7)-a(13) from _Giovanni Resta_, Jul 06 2016