OFFSET
2,2
FORMULA
a(n)=A091534(n, 4), n>=2.
a(n)= (3^(2*n))*(6*risefac(2/3, n)*risefac(1/3, n) - 4*n!*risefac(2/3, n) + risefac(4/3, n)*n!)/4!, with risefac(x, n)=Pochhammer(x, n).
E.g.f.: (6*hypergeom([2/3, 1/3], [], 9*x) - 4*hypergeom([1, 2/3], [], 9*x) + hypergeom([4/3, 1], [], 9*x) - 3)/4!.
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Wolfdieter Lang, Feb 13 2004
STATUS
approved