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 A030560 #6 Mar 30 2012 18:56:18 %S A030560 1,1,1,1,1,1,1,1,3,1,1,1,1,1,1,1,1,1,2,1,1,1,1,1,1,1,1,1,1,2,1,1,1,1, %T A030560 1,1,1,1,1,1,2,1,1,1,1,1,1,1,2,1,1,1,1,1,2,1,1,1,1,1,2,1,1,1,1,1,2,2, %U A030560 2,2,2,5,1,1,1,1,1,2,1,1,1,1,1,1,1,1,2,1 %N A030560 Length of n-th run of digit 4 in A030548. %K A030560 nonn,base %O A030560 1,9 %A A030560 _Clark Kimberling_