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 A031254 #4 Mar 30 2012 18:56:21 %S A031254 4,14,24,25,27,30,40,55,63,66,70,85,99,100,102,105,115,130,138,141, %T A031254 145,160,174,175,176,178,179,182,183,186,190,194,196,198,202,206,210, %U A031254 214,216,218,222,227,231,236,256,275,276,279,283 %N A031254 Position of n-th 0 in A031253. %K A031254 nonn %O A031254 1,1 %A A031254 _Clark Kimberling_