A022474 Number of 3's in n-th term of A022470.

0, 0, 0, 1, 1, 1, 2, 3, 3, 6, 7, 7, 11, 15, 14, 24, 30, 38, 48, 73, 83, 114, 155, 191, 251, 336, 426, 560, 737, 964, 1237, 1628, 2135, 2726, 3622, 4680, 6104, 7948, 10430, 13504, 17662, 23081, 29965, 39050, 51143, 66276, 86674, 112986, 147161, 191843, 250259

Offset: 1

Author

Clark Kimberling

Keywords

• nonn

Links

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

Programs

Mathematica

p={4,-7,7,-12,9,-4,6,-6,5,-5,10,-12,10,-11,8,-6,4,-2,5,-4,1,2,-9,16,-15,5,-6,0,3,12,-8,2,-6,-4,-3,12,-10,18,-8,3,-8,0,5,-6,7,-8,0,10,-9,4,-6,-2,11,0,2,-5,0,-3,1,-1,0,3,1,-2,-1,0,1,1,0,-1,0,0,0}; 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 23 2013 *)