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A324425
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a(n) = Product_{i=1..n, j=1..n, k=1..n} (i^2 + j^2 + k^2).
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9
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OFFSET
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0,2
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COMMENTS
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(a(n)^(1/n^3))/n^2 tends to 0.828859579669279... = A306617.
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LINKS
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MAPLE
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a:= n-> mul(mul(mul(i^2+j^2+k^2, i=1..n), j=1..n), k=1..n):
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MATHEMATICA
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Table[Product[i^2+j^2+k^2, {i, 1, n}, {j, 1, n}, {k, 1, n}], {n, 1, 6}]
Clear[a]; a[n_] := a[n] = If[n == 1, 3, a[n-1] * Product[k^2 + j^2 + n^2, {j, 1, n}, {k, 1, n}]^3 * (3*n^2) / (Product[k^2 + 2*n^2, {k, 1, n}]^3)]; Table[a[n], {n, 1, 6}] (* Vaclav Kotesovec, Mar 27 2019 *)
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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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