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A301518 a(n) = [x^n] Product_{k>=1} (1 + x^(k^2))^n. 2

%I #9 Mar 23 2018 05:55:58

%S 1,1,1,1,5,26,91,246,589,1468,4226,13311,41471,122864,351184,1001876,

%T 2920957,8698612,26070130,77707056,229959130,679050870,2011457295,

%U 5986185690,17866178695,53343031301,159149943668,474683353849,1416730630936,4233405443596

%N a(n) = [x^n] Product_{k>=1} (1 + x^(k^2))^n.

%H Vaclav Kotesovec, <a href="/A301518/b301518.txt">Table of n, a(n) for n = 0..1000</a>

%F a(n) ~ c * d^n / sqrt(n), where d = 3.04074590736461391963643911... and c = 0.2268848664201836146769277...

%t Table[SeriesCoefficient[Product[(1 + x^(k^2))^n, {k, 1, n}], {x, 0, n}], {n, 0, 30}]

%Y Cf. A033461, A281790, A291649, A300974.

%K nonn

%O 0,5

%A _Vaclav Kotesovec_, Mar 23 2018

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Last modified April 24 07:17 EDT 2024. Contains 371920 sequences. (Running on oeis4.)