A022467 Number of 2's in n-th term of A007651.

0, 0, 1, 1, 2, 2, 3, 2, 3, 4, 8, 10, 14, 18, 24, 28, 41, 56, 69, 91, 123, 164, 221, 286, 366, 494, 636, 832, 1095, 1423, 1847, 2440, 3154, 4166, 5366, 7025, 9119, 11925, 15495, 20259, 26320, 34409, 44827, 58432, 76193, 99353, 129347, 168789, 219947, 286629

Offset: 1

Author

Clark Kimberling

Keywords

• nonn

Links

• Peter J. C. Moses, Table of n, a(n) for n = 1..1000

Programs

Mathematica

p={-12,20,-11,8,9,-30,39,-58,67,-63,29,-14,0,39,15,-63,-11,30,31,22,-11,-21,23,-46,34,-46,60,26,-64,20,-77,59,41,-7,-32,-14,-6,9,5,16,1,33,-35,0,-64,38,25,38,3,-49,-27,1,11,21,2,-1,13,-9,-14,-11,1,14,11,2,-6,-8,-5,2,5,3,1,-1,-1,-2,0,0,1,0,0}; 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 24 2013 *)