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A187664
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Convolution of the (signless) central Lah numbers (A187535) and the (signless) central Stirling numbers of the first kind (A187646).
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0
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1, 3, 49, 1483, 67615, 4173203, 326208269, 30880075203, 3430574739759, 437145190334383, 62803806114813801, 10038354053796477099, 1766255133182030548351, 339166069936077378326187, 70571377417819411767223541
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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(Lah(2k,k)s(2n-2k,n-k)),k=0..n)
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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)*abs(combinat[stirling1](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]Abs[StirlingS1[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)*abs(stirling1(2*n-2*k, n-k)), k, 0, n), n, 0, 12);
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CROSSREFS
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KEYWORD
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nonn,easy
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AUTHOR
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STATUS
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approved
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