OFFSET
1,1
COMMENTS
Product of next n factorials gives this sequence, while product of first n factorials = superfactorial is A000178. If superfactorial is sf(n) then this function, "uppersuperfactorial", is usf(n)= sf(2n)/sf(n).
FORMULA
product(i!, i=n+1, 2n).
a(n) ~ 2^(2*n^2 + 5*n/2 + 5/12) * n^(n*(3*n/2+1)) * Pi^(n/2) / exp(n*(9*n+4)/4). - Vaclav Kotesovec, Jul 11 2015
MATHEMATICA
Table[Product[i!, {i, n+1, 2n}], {n, 10}]
CROSSREFS
KEYWORD
nonn
AUTHOR
Zak Seidov, Sep 22 2002
STATUS
approved