OFFSET
0,3
FORMULA
a(n) = (-1/2)^n*Pochhammer((b(n)-2*n-1)/2, n)*Pochhammer((-b(n)-2*n-1)/2, n), where b(n) = sqrt(A033996(n) + 9).
a(n) ~ sqrt(Pi) * 2^(n+2) * n^(2*n - 3/2) / exp(2*n). - Vaclav Kotesovec, Jun 27 2024
MATHEMATICA
PROG
(PARI) a(n) = vecprod(vector(n, k, n*(k - 1) - k*(k - 3)/2)); \\ Michel Marcus, Jun 25 2024
CROSSREFS
KEYWORD
nonn
AUTHOR
Stefano Spezia, Jun 25 2024
STATUS
approved