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 A324425 a(n) = Product_{i=1..n, j=1..n, k=1..n} (i^2 + j^2 + k^2). 4
 3, 5668704, 550388591715704109656479285248, 152455602303300418998634460043817052571893573096619261814850281699755319515987050496 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS (a(n)^(1/n^3))/n^2 tends to 0.828859579669279... = A306617. LINKS MATHEMATICA 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 *) CROSSREFS Cf. A079478, A306594, A324403, A306617. Sequence in context: A137131 A229725 A244113 * A117721 A229092 A058469 Adjacent sequences:  A324422 A324423 A324424 * A324426 A324427 A324428 KEYWORD nonn AUTHOR Vaclav Kotesovec, Feb 27 2019 STATUS approved

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Last modified December 6 13:24 EST 2021. Contains 349563 sequences. (Running on oeis4.)