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 A031245 #9 Apr 19 2020 17:38:55 %S A031245 1,1,1,1,1,3,1,1,1,1,1,1,1,1,2,1,1,1,1,1,1,1,1,2,1,1,1,1,2,1,1,1,1,2, %T A031245 1,1,1,1,2,1,1,2,2,5,2,1,1,2,1,1,1,1,1,1,1,1,2,1,1,1,1,1,1,1,1,2,1,1, %U A031245 1,1,1,1,1,1,2,1,1,1,1,1,1,1,1,2,1,1,1 %N A031245 Length of n-th run of digit 3 in A031235. %K A031245 nonn,base %O A031245 1,6 %A A031245 _Clark Kimberling_ %E A031245 a(84) corrected by _Sean A. Irvine_, Apr 19 2020