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 A031009 #4 Mar 30 2012 18:56:19 %S A031009 1,8,9,10,12,14,16,18,20,23,37,51,65,79,93,94,96,99,102,105,108,111, %T A031009 113,114,115,116,117,119,120,122,123,125,126,128,129,131,132,135,136, %U A031009 138,141,144,147,150,153,156,157,159,162,165,168 %N A031009 Position of n-th 1 in A031007. %K A031009 nonn %O A031009 1,2 %A A031009 _Clark Kimberling_