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 A031047 #4 Mar 30 2012 18:56:20 %S A031047 1,9,10,11,13,15,17,19,21,23,26,42,58,74,90,106,122,123,125,128,131, %T A031047 134,137,140,143,145,146,147,148,149,151,152,154,155,157,158,160,161, %U A031047 163,164,166,167,170,171,173,176,179,182,185,188 %N A031047 Position of n-th 1 in A031045. %K A031047 nonn %O A031047 1,2 %A A031047 _Clark Kimberling_