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A325951
G.f.: 1/(1-x)^3 * Product_{k>=1} (1 + x^k).
1
1, 4, 10, 21, 39, 67, 109, 170, 256, 375, 537, 754, 1041, 1416, 1901, 2523, 3314, 4312, 5563, 7121, 9050, 11426, 14338, 17890, 22204, 27422, 33709, 41257, 50288, 61058, 73863, 89043, 106988, 128146, 153029, 182222, 216393, 256302, 302813, 356908, 419700
OFFSET
0,2
FORMULA
a(n) ~ 2 * 3^(5/4) * n^(3/4) * exp(Pi*sqrt(n/3)) / Pi^3.
MATHEMATICA
nmax = 50; CoefficientList[Series[(1/(1-x)^3 * Product[1+x^k, {k, 1, nmax}]), {x, 0, nmax}], x]
CROSSREFS
KEYWORD
nonn
AUTHOR
Vaclav Kotesovec, May 28 2019
STATUS
approved