OFFSET
2,1
COMMENTS
FORMULA
PRODUCT[k=2..n](k^3+1) = PRODUCT[k=2..n]A001093(k).
a(n) ~ sqrt(2*Pi) * cosh(sqrt(3)*Pi/2) * n^(3*n+3/2) / exp(3*n). - Vaclav Kotesovec, Jul 11 2015
EXAMPLE
a(2) = 2^3+1 = 9. a(3) = (2^3+1)*(3^3+1) = 9 * 28 = 252. a(4) = (2^3+1)*(3^3+1)*(4^3+1) = 9 * 28 * 65 = 16380.
MATHEMATICA
Table[Product[(k^3+1), {k, 2, n}], {n, 2, 20}] (* Vaclav Kotesovec, Jul 11 2015 *)
FoldList[Times, Range[2, 20]^3+1] (* Harvey P. Dale, Oct 15 2017 *)
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
Jonathan Vos Post, Mar 23 2009
STATUS
approved