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 A031052 #4 Mar 30 2012 18:56:20 %S A031052 6,20,36,52,68,84,89,91,93,95,97,99,100,101,103,116,138,162,186,210, %T A031052 234,258,265,268,271,274,277,280,282,283,286,306,330,354,378,402,426, %U A031052 450,457,460,463,466,469,472,474,475,478,498,522 %N A031052 Position of n-th 6 in A031045. %K A031052 nonn %O A031052 1,1 %A A031052 _Clark Kimberling_