OFFSET
0,2
LINKS
Harvey P. Dale, Table of n, a(n) for n = 0..144
Erhan Gürela, Ali Ulas Özgür Kisisel, A note on the products (1^mu + 1)(2^mu + 1)···(n^mu + 1), Journal of Number Theory, Volume 130, Issue 1, January 2010, Pages 187-191.
FORMULA
a(n) ~ 2 * (cosh(sqrt(2)*Pi) - cos(sqrt(2)*Pi)) * n^(4*n+2) / exp(4*n).
a(n) ~ A258870 * (n!)^4. - Vaclav Kotesovec, May 16 2022
MATHEMATICA
Table[Product[k^4 + 1, {k, 0, n}], {n, 0, 15}]
FoldList[Times, Range[0, 15]^4+1] (* Harvey P. Dale, Nov 01 2022 *)
PROG
(PARI) a(n) = prod(k=1, n, 1+k^4); \\ Michel Marcus, Jan 25 2016
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Vaclav Kotesovec, Feb 23 2015
STATUS
approved