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 A316839 #7 Jul 23 2018 09:52:29 %S A316839 3,11,18,26,32,40,47,55,59,67,74,82,88,96,103,111,119,126,134,140,148, %T A316839 155,163,167,175,182,190,196,204,211,219,226,234,240,248,255,263,267, %U A316839 275,282,290,296,304,311,319,327,334,342,348,356,363,371,375,383,390,398,404,412,419,427 %N A316839 Indices of 2's in A254990. %H A316839 Seiichi Manyama, <a href="/A316839/b316839.txt">Table of n, a(n) for n = 1..10000</a> %Y A316839 Cf. A254990, A316837, A316838, A316840. %K A316839 nonn %O A316839 1,1 %A A316839 _N. J. A. Sloane_, Jul 22 2018