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 A191209 #4 Mar 30 2012 18:57:31 %S A191209 1,4,5,11,14,16,17,20,38,44,47,50,53,56,62,64,68,80,101,128,134,146, %T A191209 152,155,161,170,176,182,188,194,200,206,212,224,242,248,256,272,320, %U A191209 344,398,404,425,452,458,479,485,506,512,530,536,560,566,578,584,602,608,614,620,638,644,674,680,704 %N A191209 Integers in (A191142)/4; contains A191142 as a proper subsequence. %C A191209 See A191142. %t A191209 (See A191142.) %Y A191209 Cf. A191142, A191113. %K A191209 nonn %O A191209 1,2 %A A191209 _Clark Kimberling_, May 28 2011