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A357194
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a(n) = n! * Sum_{k=0..floor(n/3)} k^(3*n)/k!.
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2
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1, 0, 0, 6, 24, 120, 94372560, 5284828080, 338228714880, 461220488356944960, 124524904888012809600, 36983489578531184304000, 94262861823240343196388902400, 78420937396722501660156363686400, 70262981254649802508019882162611200
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OFFSET
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0,4
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LINKS
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FORMULA
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E.g.f.: Sum_{k>=0} (k^3 * x)^(3 * k) / (k! * (1 - k^3 * x)).
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PROG
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(PARI) a(n) = n!*sum(k=0, n\3, k^(3*n)/k!);
(PARI) my(N=20, x='x+O('x^N)); Vec(serlaplace(sum(k=0, N, (k^3*x)^(3*k)/(k!*(1-k^3*x)))))
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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STATUS
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approved
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