A022473 - OEIS

%I #8 Jun 27 2013 13:12:34

%S 1,1,1,1,2,3,4,5,7,7,11,14,16,22,34,37,56,70,94,113,161,191,252,341,

%T 435,568,762,973,1276,1661,2169,2817,3657,4811,6200,8178,10603,13878,

%U 18015,23582,30617,39919,52100,67898,88298,115624,150200,196145,255716,333151

%N Number of 2's in n-th term of A022470.

%H Peter J. C. Moses, <a href="/A022473/b022473.txt">Table of n, a(n) for n = 1..1000</a>

%t p={-6,11,-10,17,-19,14,-23,16,-14,17,-14,19,-21,29,-11,2,-19,18,-2,7,-19,-18,37,-16,18,-19,11,-10,-1,-25,27,12,25,-22,-6,-22,6,-9,15,-12,33,-3,-11,-3,-28,24,16,-7,7,-19,8,4,-16,0,-2,18,1,1,-7,-2,1,-2,-2,3,3,1,-2,-3,0,2,1,0,-1}; q={-6,9,-9,18,-16,11,-14,8,-1,5,-7,-2,-8,14,5,5,-19,-3,6,7,6,-16,7,-8,22,-17,12,-7,-5,-7,8,-4,7,9,-13,4,6,-14,14,-19,7,13,-2,4,-18,0,1,4,12,-8,5,0,-8,-1,-7,8,5,2,-3,-3,0,0,0,0,2,1,0,-3,-1,1,1,1,-1}; gf=Fold[x #1+#2&,0,p]/Fold[x #1+#2&,0,q]; CoefficientList[Series[gf,{x,0,99}],x] (* _Peter J. C. Moses_, Jun 23 2013 *)

%K nonn

%O 1,5

%A _Clark Kimberling_