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 A191200 #4 Mar 30 2012 18:57:31 %S A191200 1,2,4,6,7,10,13,18,19,22,26,30,31,40,42,54,55,58,67,74,78,79,90,91, %T A191200 94,106,121,122,126,127,162,163,166,170,175,202,218,222,223,234,235, %U A191200 238,270,271,274,283,298,314,318,319,362,364,366,367,378,379,382,426,486,487,490,499,506,510,511,526,607,650,654,655,666,667,670 %N A191200 Integers in (-1+A191138)/3; contains A191138 as a proper subsequence. %C A191200 See A191138. %t A191200 (See A191138.) %Y A191200 Cf. A191138, A191113. %K A191200 nonn %O A191200 1,2 %A A191200 _Clark Kimberling_, May 28 2011