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A280277 G.f.: Product_{k>=1} (1 + x^k) / (1 - x^(k^3)). 4

%I #8 Jan 28 2024 09:00:28

%S 1,2,3,5,7,10,14,19,26,35,46,60,77,98,124,156,195,242,299,367,448,545,

%T 660,796,957,1146,1368,1629,1933,2287,2700,3178,3732,4373,5112,5964,

%U 6944,8068,9357,10832,12517,14440,16632,19126,21960,25178,28825,32954,37625

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

%C Convolution of A000009 and A003108.

%H Vaclav Kotesovec, <a href="/A280277/b280277.txt">Table of n, a(n) for n = 0..10000</a>

%H Vaclav Kotesovec, <a href="/A280277/a280277.jpg">Graph - The asymptotic ratio (100000 terms)</a>

%F 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).

%t nmax=80; CoefficientList[Series[Product[(1+x^k)/(1-x^(k^3)), {k, 1, nmax}], {x, 0, nmax}], x]

%Y Cf. A000009, A003108, A102108, A280264, A280276, A369571, A369573.

%K nonn

%O 0,2

%A _Vaclav Kotesovec_, Dec 30 2016

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Last modified September 13 18:22 EDT 2024. Contains 375910 sequences. (Running on oeis4.)