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

%I #6 Aug 24 2018 13:15:26

%S 1,1,2,42,600,28920,374285520,128100273840,131101518683520,

%T 143354704247556480,173401404266683545849388800,

%U 2538767479410416957720411116800,105287752487031026606448840363801600,4510685217145833106538730603088118860800,288804138719404983322786510403231912442931200

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

%H Vaclav Kotesovec, <a href="/A318247/b318247.txt">Table of n, a(n) for n = 0..65</a>

%t nmax = 15; Table[SeriesCoefficient[Product[(1+n!*x^k), {k, 1, n}], {x, 0, n}], {n, 0, nmax}]

%Y Cf. A077365, A265950, A292306, A292414, A318246.

%K nonn

%O 0,3

%A _Vaclav Kotesovec_, Aug 22 2018