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A187662
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Convolution of the (signless) central Lah numbers (A187535) and the central Stirling numbers of the second kind (A007820).
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0
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1, 3, 45, 1340, 62133, 3926607, 313159138, 30077004204, 3373855596485, 432604296358341, 62396125789568633, 9997677582465775336, 1761777732880595653932, 338625441643226149909356, 70500059235176885929427760
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OFFSET
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0,2
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LINKS
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Table of n, a(n) for n=0..14.
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FORMULA
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a(n) = sum(Lah(2k,k)S(2n-2k,n-k)),k=0..n).
a(n) ~ 2^(4*n) * n^n / (exp(n) * sqrt(2*Pi*n)). - Vaclav Kotesovec, May 21 2014
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MAPLE
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L := n -> if n=0 then 1 else binomial(2*n-1, n-1)*(2*n)!/n! fi;
seq(sum(L(k)*combinat[stirling2](2*(n-k), n-k), k=0..n), n=0..12);
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MATHEMATICA
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L[n_] := If[n == 0, 1, Binomial[2n - 1, n - 1](2n)!/n!]
Table[Sum[L[k]StirlingS2[2n - 2k, n - k], {k, 0, n}], {n, 0, 14}]
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PROG
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(Maxima) L(n):= if n=0 then 1 else binomial(2*n-1, n-1)*(2*n)!/n!;
makelist(sum(L(k)*stirling2(2*n-2*k, n-k), k, 0, n), n, 0, 12);
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CROSSREFS
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Cf. A187535, A007820.
Sequence in context: A009088 A245066 A352409 * A113065 A144949 A144950
Adjacent sequences: A187659 A187660 A187661 * A187663 A187664 A187665
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KEYWORD
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nonn,easy
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AUTHOR
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Emanuele Munarini, Mar 12 2011
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STATUS
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approved
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