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A187542
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Convolutions of the central Lah numbers (A187535).
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11
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1, 4, 76, 2544, 123696, 7942080, 635633280, 61009159680, 6831940227840, 874493448514560, 125946241018214400, 20156433977646489600, 3548609812373223628800, 681555522002874494976000, 141810253720479017017344000
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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(L(k)L(n-k),k=0..n), where L(n) is a central Lah number.
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MAPLE
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a := n -> if n=0 then 1 else binomial(2*n-1, n-1)*(2*n)!/n! fi;
seq(sum(a(k)*a(n-k), k=0..n), n=0..12);
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MATHEMATICA
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a[n_] := If[n == 0, 1, Binomial[2n - 1, n - 1](2n)!/n!]
Table[Sum[a[k]a[n - k], {k, 0, n}], {n, 0, 20}]
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PROG
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(Maxima) a(n) := if n=0 then 1 else binomial(2*n-1, n-1)*(2*n)!/n!;
makelist(sum(a(k)*a(n-k), k, 0, n), n, 0, 12);
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CROSSREFS
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Cf. A187536, A008297, A111596, A187536, A187538, A187539, A187540, A187543, A187544, A187545, A187546, A187547, A187548.
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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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