OFFSET
0,2
FORMULA
a(n) = 3*((3*n+1)*a(n-1) + (3*n+2)*a(n-2))/n for n > 1.
a(n) = Sum_{k=0..n} (-9)^k * binomial(-4/3,k) * binomial(k,n-k).
PROG
(PARI) a(n) = sum(k=0, n, (-9)^k*binomial(-4/3, k)*binomial(k, n-k));
CROSSREFS
KEYWORD
nonn
AUTHOR
Seiichi Manyama, Oct 21 2024
STATUS
approved