A266945 - OEIS

%I #7 Dec 13 2023 08:37:29

%S 1,6,30,122,450,1518,4830,14586,42330,118622,322974,857298,2226586,

%T 5672046,14205654,35040722,85269114,204971478,487307542,1146995154,

%U 2675265522,6188176838,14205568950,32383725450,73352114450,165171276822,369904716750,824244212554

%N Expansion of Product_{k>=1} 1 / (1 - 2*x^k)^3.

%H Vaclav Kotesovec, <a href="/A266945/b266945.txt">Table of n, a(n) for n = 0..1000</a>

%F a(n) ~ c * n^2 * 2^n, where c = 1/(2*A048651^3) = 1/(2*QPochhammer(1/2)^3) = 20.760229307499152409838537... .

%t nmax = 40; CoefficientList[Series[Product[1/(1-2*x^k)^3, {k, 1, nmax}], {x, 0, nmax}], x]

%Y Cf. A070933, A266943.

%K nonn

%O 0,2

%A _Vaclav Kotesovec_, Jan 06 2016