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 A031229 #11 Apr 17 2020 02:50:35 %S A031229 1,1,1,1,1,1,3,1,1,1,1,1,1,1,2,1,1,1,1,1,1,1,1,2,1,1,1,1,1,1,2,1,1,1, %T A031229 1,2,1,1,1,1,2,2,2,2,5,1,1,1,1,2,1,1,1,1,1,1,2,1,1,1,1,1,1,1,1,2,1,1, %U A031229 1,1,1,1,1,1,2,1,1,1,1,1,1,1,1,2,1,1,1 %N A031229 Length of n-th run of digit 3 in A031219. %K A031229 nonn,base %O A031229 1,7 %A A031229 _Clark Kimberling_ %E A031229 a(84) corrected by _Sean A. Irvine_, Apr 16 2020