%I #2 Mar 30 2012 18:57:10
%S 0,1,0,1,1,3,3,6,8,12,18,26,40,60,89,135,201,303,453,680,1022,1528,
%T 2299,3443,5176,7750,11642,17443,26172,39246,58874,88308,132461,
%U 198694,298094,447097,670645,1005992,1508898,2263540
%N Number of 2's in row n of A143589 (a Kolakoski fan).
%C A143590 = A143591 + A143592.
%e The first 6 rows of A143589 are 1; 2; 1,1; 2,1; 1,1,2; 2,1,2,2. The
%e respective numbers of 1's are 0,1,0,1,1,3.
%Y Cf. A000002, A143587, A143589, A143590, A143591.
%K nonn
%O 1,6
%A _Clark Kimberling_, Aug 25 2008