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A367472
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Expansion of e.g.f. 1 / (4 - 3 * exp(x))^2.
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3
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1, 6, 60, 816, 13992, 289176, 6990360, 193432056, 6028092312, 208891033656, 7966989308760, 331618933474296, 14958464943057432, 726825458489514936, 37846457287387667160, 2102428978611587164536, 124109778776508893651352, 7758254465575303379273016
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OFFSET
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0,2
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LINKS
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FORMULA
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a(n) = Sum_{k=0..n} 3^k * (k+1)! * Stirling2(n,k).
a(0) = 1; a(n) = 3*Sum_{k=1..n} (k/n + 1) * binomial(n,k) * a(n-k).
a(0) = 1; a(n) = 6*a(n-1) - 4*Sum_{k=1..n-1} (-1)^k * binomial(n-1,k) * a(n-k).
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PROG
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(PARI) a(n) = sum(k=0, n, 3^k*(k+1)!*stirling(n, k, 2));
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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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