OFFSET
0,2
FORMULA
G.f.: (2*g-1)*(2*g^2-2*g+1)/((3*g-1)*(g-1)^4) where g*(1-g)^2 = x. - Mark van Hoeij, Nov 09 2011
MATHEMATICA
Table[Binomial[3n, n]-Binomial[3n, n-4], {n, 0, 20}] (* Harvey P. Dale, Dec 14 2012 *)
PROG
(PARI) a(n) = binomial(3*n, n) - binomial(3*n, n-4); \\ Michel Marcus, May 10 2020
CROSSREFS
KEYWORD
nonn
AUTHOR
EXTENSIONS
More terms from Ralf Stephan, Jan 09 2005
STATUS
approved