A128569 Column 2 of triangle A128567.

1, 14, 117, 813, 4871, 27743, 151208, 804065, 4185683, 21472005, 108766010, 545507633, 2712801330, 13394412999, 65722444172, 320721839860, 1557502222385, 7530671086667, 36267851679585, 174038009185816, 832392015517829, 3969017685816667, 18871416851149078

Offset: 0

Author

Paul D. Hanna, Mar 12 2007

Keywords

• nonn

Comments

A128567 is the matrix square of Parker's partition triangle A047812.

Crossrefs

Cf. A047812, A128567, A128568 (column 1), A128602 (row sums).

Programs

PARI

{a(n)=local(M);M=matrix(n+3,n+3,r,c,if(r
				

Formula

a(n) = Sum_{s=2..n+2} A047812(n+3,s)*A047812(s+1,2) for n >= 0. - Petros Hadjicostas, May 31 2020