A064057 Eighth column of quintinomial coefficients.

2, 18, 80, 255, 666, 1520, 3144, 6030, 10890, 18722, 30888, 49205, 76050, 114480, 168368, 242556, 343026, 477090, 653600, 883179, 1178474, 1554432, 2028600, 2621450, 3356730, 4261842, 5368248

Offset: 0

Author

Wolfdieter Lang, Aug 29 2001

Keywords

• nonn
• easy

Crossrefs

Cf. A064056 (seventh column).

Formula

a(n) = A035343(n+2, 7)= binomial(n+3, 3)*(n+14)*(n^3+15*n^2+116*n+120)/(7!/3!).

G.f.: (2+2*x-8*x^2+7*x^3-2*x^4 )/(1-x)^8; numerator polynomial is N5(7, x) from the array A063422.

a(n) = 2*C(n+2,2) + 12*C(n+2,3) + 20*C(n+2,4) + 15*C(n+2,5) + 6*C(n+2,6) + C(n+2,7) (see comment in A213887). - Vladimir Shevelev and Peter J. C. Moses, Jun 22 2012