OFFSET
0,1
FORMULA
a(n) = 2*(n + 4)*a(n - 1) / n for n >= 2.
a(n) = 2^(n - 3)*(n + 1)*(n + 2)*(n + 3)*(n + 4).
a(n) = n! * [x^n] (2*x^4 + 16*x^3 + 36*x^2 + 24*x + 3)*exp(2*x).
a(n) ~ 2^(n - 3) * n^4.
MAPLE
a := n -> 2^(n - 3)*(n + 1)*(n + 2)*(n + 3)*(n + 4): seq(a(n), n = 0..25);
CROSSREFS
KEYWORD
nonn
AUTHOR
Peter Luschny, May 29 2021
STATUS
approved