A280278 G.f.: Product_{k>=1} (1 + x^(k^3)) / (1 - x^k).

1, 2, 3, 5, 8, 12, 18, 26, 38, 54, 75, 103, 141, 190, 254, 337, 444, 580, 754, 973, 1250, 1597, 2030, 2568, 3237, 4061, 5076, 6322, 7847, 9705, 11968, 14711, 18033, 22043, 26873, 32677, 39642, 47972, 57924, 69787, 83904, 100667, 120547, 144072, 171876, 204677

Offset

0,2

Comments

Convolution of A279329 and A000041.

Links

Vaclav Kotesovec, Table of n, a(n) for n = 0..10000

Formula

a(n) ~ exp(Pi*sqrt(2*n/3) + (2^(1/3) - 1) * Gamma(1/3) * Zeta(4/3) * n^(1/6) / (2^(1/6) * 3^(5/6) * Pi^(1/3))) / (4*sqrt(6)*n).

Mathematica

nmax=60; CoefficientList[Series[Product[(1+x^(k^3))/(1-x^k), {k, 1, nmax}], {x, 0, nmax}], x]

Crossrefs

Cf. A000041, A264393, A279329, A280204.

Sequence in context: A200310 A328085 A001524 * A136275 A344002 A328170

Adjacent sequences: A280275 A280276 A280277 * A280279 A280280 A280281

Keyword

nonn

Author

Vaclav Kotesovec, Dec 30 2016

Status

approved