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 A143590 #2 Mar 30 2012 18:57:10 %S A143590 1,1,2,2,3,4,7,10,16,24,36,54,80,120,180,269,404,605,908,1361,2041, %T A143590 3063,4591,6890,10333,15509,23259,34901,52344,78516,117762,176636, %U A143590 264944,397405,596099,894193,1341290,2011935,3017927,4526825 %N A143590 Length of row n of A143589 (a Kolakoski fan). %C A143590 Conjecture (following Benoit Cloitre's conjecture at A111090): %C A143590 if L=A143489, then L(n)*(2/3)^n approaches a constant. %e A143590 The first 6 rows of A143589 are 1; 2; 1,1; 2,1; 1,1,2; 2,1,2,2. Their %e A143590 lengths are 1,1,2,2,3,4. %Y A143590 Cf. A000002, A111090, A143477, A143586, A143489. %K A143590 nonn %O A143590 1,3 %A A143590 _Clark Kimberling_, Aug 25 2008