A128568 Column 1 of triangle A128567.

1, 6, 31, 133, 587, 2531, 10950, 47185, 203704, 879711, 3804530, 16464710, 71312805, 309083291, 1340546867, 5817555402, 25258769216, 109711224970, 476675868834, 2071569641859, 9004430215111, 39144480326143, 170184867215647, 739924236443359, 3217001700174226

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. A007042, A047812, A128567, A128569 (column 2), A128602 (row sums).

Programs

PARI

{a(n)=local(M);M=matrix(n+2,n+2,r,c,if(r
				

Formula

a(n) = Sum_{s=1..n+1} A047812(n+2,s)*A047812(s+1,1) = Sum_{s=1..n+1} A047812(n+2,s)*A007042(s+1) for n >= 0. - Petros Hadjicostas, May 31 2020