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A308652
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a(n) = Product_{k=1..n} sigma(n,k).
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1
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1, 1, 5, 252, 380562, 26605273464, 146392210728465000, 84641321148614770425516288, 7097143900835489590932722296959504144, 109983275218947201453245400551817117367706036248320, 397899007017966277799025689101644536884667639093655295898437500000
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OFFSET
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0,3
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LINKS
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FORMULA
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a(n) ~ (n!)^n.
a(n) ~ 2^(n/2) * Pi^(n/2) * n^(n*(2*n+1)/2) / exp(n^2-1/12).
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MAPLE
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with(NumberTheory): seq(product(sigma[n](k), k = 1..n), n = 0..10);
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MATHEMATICA
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Table[Product[DivisorSigma[n, k], {k, 1, n}], {n, 1, 10}]
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PROG
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(PARI) a(n) = prod(k=1, n, sigma(k, n));
for(n=1, 10, print1(a(n), ", "))
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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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