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 A031259 #4 Mar 30 2012 18:56:21 %S A031259 1,6,2,8,3,32,5,1,7,39,6,42,11,45,13,2,15,12,17,54,19,8,21,18,23,3,26, %T A031259 205,29,188,32,238,35,242,38,5,41,10,44,254,1,258,50,262,53,243,7,20, %U A031259 59,274,39,278,65,282,28,240,9,290,6,294,42,298 %N A031259 a(n)=least k such that base 5 representation of n begins at s(k), where s=A031253. %K A031259 nonn %O A031259 1,2 %A A031259 _Clark Kimberling_