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 A031263 #9 Apr 20 2020 19:35:56 %S A031263 1,2,1,1,1,1,1,2,1,1,1,1,1,2,1,1,1,1,2,1,1,2,4,1,1,1,1,1,1,1,1,1,1,2, %T A031263 1,1,1,1,1,1,1,1,2,1,1,1,1,1,1,1,1,1,2,2,2,1,1,1,1,1,2,1,1,1,1,1,1,1, %U A031263 1,2,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,2,3 %N A031263 Length of n-th run of digit 3 in A031253. %K A031263 nonn,base %O A031263 1,2 %A A031263 _Clark Kimberling_ %E A031263 a(86) corrected by _Sean A. Irvine_, Apr 20 2020