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A291547
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a(n) = ((2*n-1)!!)^n.
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1
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1, 9, 3375, 121550625, 753631499840625, 1261673443947253805015625, 822952789790387281855874669859609375, 285018362247755338974104595257347347998199462890625, 68512882179510153729154120317673085873841328059500855014801025390625
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OFFSET
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1,2
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LINKS
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FORMULA
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a(n) = ((2*n)!/n!)^n / 2^(n^2).
a(n) ~ 2^(n^2 + n/2) * n^(n^2) / exp(n^2 + 1/24).
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MATHEMATICA
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Table[Product[2*k - 1, {k, 1, n}]^n, {n, 1, 10}]
Table[((2*n - 1)!!)^n, {n, 1, 10}]
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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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