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 A031115 #4 Mar 30 2012 18:56:21 %S A031115 3,9,10,30,37,61,72,82,85,89,90,93,96,97,104,120,138,140,144,150,178, %T A031115 179,182,186,200,210,219,226,238,241,255,256,269,276,279,285,292,306, %U A031115 309,327,343,357,364,377,382,384,385,387,413 %N A031115 Position of n-th 3 in A031111. %K A031115 nonn %O A031115 1,1 %A A031115 _Clark Kimberling_