A143058 A007318 * [1, 6, 7, 1, 0, 0, 0, ...].

1, 7, 20, 41, 71, 111, 162, 225, 301, 391, 496, 617, 755, 911

Offset: 1

Author

Gary W. Adamson, Jul 20 2008

Keywords

• nonn

Examples

			a(4) = 41 = (1, 3, 3, 1) dot (1, 6, 7, 1) = (1 + 18 + 21 + 1).
		

Crossrefs

Cf. A008278.

Formula

Binomial transform of [1, 6, 7, 1, 0, 0, 0, ...], where (1, 6, 7, 1) = row 3 of triangle A008278.

From Colin Barker, Jul 24 2012: (Start)

Conjecture: a(n) = (6 - 16*n + 15*n^2 + n^3)/6.

G.f.: -x*(x^3+2*x^2-3*x-1)/(x-1)^4. (End)