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A272247
a(n) = Product_{k=0..n} (n^4 + k^4).
7
0, 2, 8704, 104372388, 3087748038656, 194985808028125000, 23467500289618753093632, 4938279594477505466022892304, 1699491802948673617630927695904768, 907214902722906584628050661111614570016, 719684491044699824651608981274624000000000000
OFFSET
0,2
FORMULA
a(n) ~ 2^(n+1/2) * (1+sqrt(2))^(sqrt(2)*n) * n^(4*n + 4) / exp((4 - Pi/sqrt(2))*n).
MATHEMATICA
Table[Product[n^4+k^4, {k, 0, n}], {n, 0, 10}]
KEYWORD
nonn,easy
AUTHOR
Vaclav Kotesovec, Apr 23 2016
STATUS
approved