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 A031228 #8 Dec 19 2021 16:33:01 %S A031228 1,1,1,1,3,1,1,1,1,1,1,1,2,1,1,1,1,1,1,1,2,1,1,1,1,2,1,2,2,5,2,1,1,1, %T A031228 2,1,1,1,1,2,1,1,1,1,1,2,1,1,1,1,1,1,1,1,2,1,1,1,1,1,1,1,1,2,1,1,1,1, %U A031228 1,1,1,1,2,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,2 %N A031228 Length of n-th run of digit 2 in A031219. %t A031228 Length/@(If[MemberQ[#,2],#,Nothing]&/@Split[Flatten[ IntegerDigits[ Range[ 400],5]]]) (* _Harvey P. Dale_, Dec 19 2021 *) %K A031228 nonn,base %O A031228 1,5 %A A031228 _Clark Kimberling_