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 A030338 #14 Jun 18 2022 15:55:26 %S A030338 1,2,1,2,1,1,1,1,3,1,1,2,1,1,3,2,3,1,1,1,1,2,1,1,1,1,2,1,1,1,1,1,1,1, %T A030338 1,2,2,4,1,1,2,1,1,2,1,1,1,1,3,1,1,2,1,1,2,1,1,1,1,4,2,2,3,2,2,4,3,4, %U A030338 1,1,1,1,2,1,1,1,1,2,1,1,1,1,1,1,1,1,2,2,3,1 %N A030338 Length of n-th run of digit 2 in A003137. %H A030338 Reinhard Zumkeller, <a href="/A030338/b030338.txt">Table of n, a(n) for n = 1..10000</a> %o A030338 (Haskell) %o A030338 import Data.List (group) %o A030338 a030338 n = a030338_list !! (n-1) %o A030338 a030338_list = map length $ filter ((== 2) . head) $ group a003137_list %o A030338 -- _Reinhard Zumkeller_, Feb 21 2013 %Y A030338 Cf. A003137. %Y A030338 Cf. A030336, A030337, A030334. %K A030338 nonn,base %O A030338 1,2 %A A030338 _Clark Kimberling_