A128554 Column 4 of triangle A128545; a(n) is the coefficient of q^(4n+16) in the central q-binomial coefficient [2n+8,n+4].

1, 7, 39, 155, 526, 1555, 4192, 10465, 24620, 55038, 117966, 243723, 487842, 949446, 1802547, 3346632, 6089910, 10881277, 19121293, 33091141, 56466398, 95105255, 158256685, 260386761, 423932473, 683409993, 1091521679, 1728156294

Offset: 0

Author

Paul D. Hanna, Mar 10 2007

Keywords

• nonn

Crossrefs

Cf. A128545; A128552, A128553.

Programs

PARI

a(n)=polcoeff(prod(j=n+5,2*n+8,1-q^j)/prod(j=1,n+4,1-q^j),4*n+16,q)