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 A097503 #16 Jan 29 2017 07:25:41 %S A097503 1,2,3,4,7,8,9,12,13,16,18,19,21,25,27,28,31,32,36,37,39,43,48,49,50, %T A097503 52,57,61,63,64,67,72,73,75,76,79,81,84,91,93,97,98,100,103,108,109, %U A097503 111,112,117,121,124,127,128,129,133,139,144,148,151,156,157,162,163,169 %N A097503 Numbers k such that A000203(k) = sigma(k) is not divisible by 6. %C A097503 Positions of nonzero terms in A084301. - _Ivan Neretin_, Jan 26 2017 %H A097503 Ivan Neretin, <a href="/A097503/b097503.txt">Table of n, a(n) for n = 1..10000</a> %t A097503 Select[Range[170], ! Divisible[DivisorSigma[1, #], 6] &] (* _Ivan Neretin_, Jan 26 2017 *) %o A097503 (PARI) isok(n) = (sigma(n) % 6) != 0; \\ _Michel Marcus_, Jan 26 2017 %Y A097503 Cf. A000203, A084301. %Y A097503 Complement of A074627. %K A097503 nonn %O A097503 1,2 %A A097503 _Labos Elemer_, Aug 23 2004 %E A097503 Definition corrected by _Ivan Neretin_, Jan 26 2017