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 A143588 #2 Mar 30 2012 18:57:10 %S A143588 0,1,2,2,3,4,6,10,15,22,33,52,74,113,168,255,377,567,850,1280,1916, %T A143588 2878,4324,6473,9720,14577,21862,32766,49150,73758,110640,165962, %U A143588 249013,373405,560201,840358,1260296,1890539,2835987,4253676,6380430,9570746 %N A143588 Number of 2's in row n of the Kolakoski fan A143477. %C A143588 A143586 = A143587 + A143588. %e A143588 The first 4 rows of A143477 are 1; 2; 22; 1122. The respective numbers of 1's are 0,1,2,2. %Y A143588 Cf. A000002, A143477, A143486, A143487. %K A143588 nonn %O A143588 1,3 %A A143588 _Clark Kimberling_, Aug 25 2008