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A098695
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a(n) = 2^(n(n-1)/2) * Product_{k=1..n} k!.
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3
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1, 1, 4, 96, 18432, 35389440, 815372697600, 263006617337856000, 1357366631815981301760000, 126095668058466123464363212800000, 234278891648287676839670388023623680000000
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OFFSET
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0,3
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COMMENTS
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LINKS
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FORMULA
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a(n) = 2^(n(n-1)/2) * Product_{k=1..n} k!.
a(n) ~ 2^(n^2/2 + 1/2)*exp(-3*n^2/4 - n + 1/12)*n^(n^2/2 + n + 5/12)*Pi^(n/2 + 1/2)/A, where A is the Glaisher-Kinkelin constant (A074962). - Ilya Gutkovskiy, Dec 11 2016
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MAPLE
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PROG
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(PARI) a(n) = 2^(n*(n-1)/2) * prod(k=1, n, k!); \\ Michel Marcus, Dec 11 2016
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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