A309678 G.f. A(x) satisfies: A(x) = A(x^4) / (1 - x)^2.

1, 2, 3, 4, 7, 10, 13, 16, 22, 28, 34, 40, 50, 60, 70, 80, 97, 114, 131, 148, 175, 202, 229, 256, 296, 336, 376, 416, 472, 528, 584, 640, 718, 796, 874, 952, 1058, 1164, 1270, 1376, 1516, 1656, 1796, 1936, 2116, 2296, 2476, 2656, 2886, 3116, 3346, 3576, 3866, 4156, 4446, 4736, 5096

Offset

0,2

Links

Table of n, a(n) for n=0..56.

Formula

G.f.: Product_{k>=0} 1/(1 - x^(4^k))^2.

Mathematica

nmax = 56; A[_] = 1; Do[A[x_] = A[x^4]/(1 - x)^2 + O[x]^(nmax + 1) // Normal, nmax + 1]; CoefficientList[A[x], x]
nmax = 56; CoefficientList[Series[Product[1/(1 - x^(4^k))^2, {k, 0, Floor[Log[4, nmax]] + 1}], {x, 0, nmax}], x]

Crossrefs

Cf. A005705, A171238, A174026, A309677, A309679.

Sequence in context: A107817 A008811 A144678 * A279225 A073149 A065461

Adjacent sequences: A309675 A309676 A309677 * A309679 A309680 A309681

Keyword

nonn

Author

Ilya Gutkovskiy, Aug 12 2019

Status

approved