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 A031241 #4 Mar 30 2012 18:56:21 %S A031241 1,2,3,4,14,6,1,10,12,24,9,18,2,22,34,11,21,30,3,4,13,23,33,42,119,48, %T A031241 14,89,104,47,6,7,67,70,50,8,17,1,110,53,10,27,98,113,56,12,37,101, %U A031241 116,194,51,126,24,179,88,66,16,9,85,125,81,18,19 %N A031241 a(n)=least k such that base 5 representation of n begins at s(k), where s=A031235. %K A031241 nonn %O A031241 1,2 %A A031241 _Clark Kimberling_