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}]
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Vaclav Kotesovec, Apr 23 2016
STATUS
approved