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G.f.: Product_{k>=1} (1 + x^(k^3)) / (1 - x^k).
4

%I #7 Jan 28 2024 09:27:06

%S 1,2,3,5,8,12,18,26,38,54,75,103,141,190,254,337,444,580,754,973,1250,

%T 1597,2030,2568,3237,4061,5076,6322,7847,9705,11968,14711,18033,22043,

%U 26873,32677,39642,47972,57924,69787,83904,100667,120547,144072,171876,204677

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

%C Convolution of A279329 and A000041.

%H Vaclav Kotesovec, <a href="/A280278/b280278.txt">Table of n, a(n) for n = 0..10000</a>

%F 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).

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

%Y Cf. A000041, A264393, A279329, A280204, A369571, A369579.

%K nonn

%O 0,2

%A _Vaclav Kotesovec_, Dec 30 2016