A022473 Number of 2's in n-th term of A022470.

1, 1, 1, 1, 2, 3, 4, 5, 7, 7, 11, 14, 16, 22, 34, 37, 56, 70, 94, 113, 161, 191, 252, 341, 435, 568, 762, 973, 1276, 1661, 2169, 2817, 3657, 4811, 6200, 8178, 10603, 13878, 18015, 23582, 30617, 39919, 52100, 67898, 88298, 115624, 150200, 196145, 255716, 333151

Offset: 1

Author

Clark Kimberling

Keywords

• nonn

Links

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

Programs

Mathematica

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 *)