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A280088 Expansion of Product_{k>=1} 1/(1 - x^k)^(k!!). 2

%I #14 May 08 2017 00:29:13

%S 1,1,3,6,17,38,112,280,882,2416,8253,24458,91051,289704,1172288,

%T 3980034,17413820,62706119,294608079,1118820630,5603910081,

%U 22328924231,118432939871,492897768426,2752203529333,11918139966134,69709167028426,313080284080648,1910245872252972,8873669214476627,56283324138424814,269790676411694902

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

%C Euler transform of the double factorials (A006882).

%H Vincenzo Librandi, <a href="/A280088/b280088.txt">Table of n, a(n) for n = 0..300</a>

%H M. Bernstein and N. J. A. Sloane, <a href="http://arXiv.org/abs/math.CO/0205301">Some canonical sequences of integers</a>, Linear Alg. Applications, 226-228 (1995), 57-72; erratum 320 (2000), 210. [Link to arXiv version]

%H M. Bernstein and N. J. A. Sloane, <a href="/A003633/a003633_1.pdf">Some canonical sequences of integers</a>, Linear Alg. Applications, 226-228 (1995), 57-72; erratum 320 (2000), 210. [Link to Lin. Alg. Applic. version together with omitted figures]

%H N. J. A. Sloane, <a href="/transforms.txt">Transforms</a>

%H <a href="/index/Fa#factorial">Index entries for sequences related to factorial numbers</a>

%F G.f.: Product_{k>=1} 1/(1 - x^k)^(k!!).

%F a(n) ~ n!!. - _Vaclav Kotesovec_, Dec 25 2016

%t nmax = 31; CoefficientList[Series[Product[1/(1 - x^k)^(k!!), {k, 1, nmax}], {x, 0, nmax}], x]

%Y Cf. A006882, A107895.

%K nonn

%O 0,3

%A _Ilya Gutkovskiy_, Dec 25 2016

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Last modified April 25 12:15 EDT 2024. Contains 371969 sequences. (Running on oeis4.)