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A280277
G.f.: Product_{k>=1} (1 + x^k) / (1 - x^(k^3)).
4
1, 2, 3, 5, 7, 10, 14, 19, 26, 35, 46, 60, 77, 98, 124, 156, 195, 242, 299, 367, 448, 545, 660, 796, 957, 1146, 1368, 1629, 1933, 2287, 2700, 3178, 3732, 4373, 5112, 5964, 6944, 8068, 9357, 10832, 12517, 14440, 16632, 19126, 21960, 25178, 28825, 32954, 37625
OFFSET
0,2
COMMENTS
Convolution of A000009 and A003108.
FORMULA
a(n) ~ exp(Pi*sqrt(n/3) + 2^(1/3) * Gamma(1/3) * Zeta(4/3) * n^(1/6) / (3^(5/6) * Pi^(1/3))) / (16*sqrt(3)*Pi*n).
MATHEMATICA
nmax=80; CoefficientList[Series[Product[(1+x^k)/(1-x^(k^3)), {k, 1, nmax}], {x, 0, nmax}], x]
KEYWORD
nonn
AUTHOR
Vaclav Kotesovec, Dec 30 2016
STATUS
approved