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 A274557 #22 Jun 14 2025 12:12:32 %S A274557 6,24,25,30,42,54,66,78,102,114,138,174,186,222,246,258,282,304,318, %T A274557 354,366,402,426,438,474,498,534,582,606,618,642,654,678,762,786,822, %U A274557 834,894,906,942,978,1002,1038,1074,1086,1146,1158,1182,1194,1266,1338,1362 %N A274557 Numbers k such that sigma(k) == 0 (mod k+6). %H A274557 Seiichi Manyama, <a href="/A274557/b274557.txt">Table of n, a(n) for n = 1..10000</a> %e A274557 sigma(6) mod (6+6) = 12 mod 12 = 0. %t A274557 Select[Range@ 1400, Mod[DivisorSigma[1, #], # + 6] == 0 &] (* _Michael De Vlieger_, Jul 05 2016 *) %o A274557 (PARI) is(n)=sigma(n)%(n+6)==0 \\ _Charles R Greathouse IV_, Jul 16 2016 %Y A274557 Cf. A000203, A045770, A067702, A088833, A181598, A274551-A274556, A274558-A274566. %K A274557 nonn %O A274557 1,1 %A A274557 _Paolo P. Lava_, Jul 05 2016