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 A031230 #12 Apr 17 2020 02:50:48 %S A031230 1,1,1,2,1,1,1,2,1,1,1,1,1,1,1,1,2,1,1,1,1,1,1,1,1,2,1,1,1,1,1,1,1,1, %T A031230 3,1,1,1,1,2,1,1,1,1,2,1,1,1,1,2,1,1,1,1,3,2,2,2,3,1,1,1,1,1,1,1,1,2, %U A031230 1,1,1,1,1,1,1,1,2,1,1,1,1,1,1,1,1,2,1 %N A031230 Length of n-th run of digit 4 in A031219. %K A031230 nonn,base %O A031230 1,4 %A A031230 _Clark Kimberling_ %E A031230 a(86) corrected by _Sean A. Irvine_, Apr 16 2020