A107704 Diagonal sums of A103209, viewed as number triangle.

1, 1, 2, 3, 8, 26, 107, 492, 2481, 13599, 81288, 531343, 3790344, 29279668, 242278645, 2125160800, 19608039385, 189437263949, 1912477987102, 20161911603747, 221869317899264, 2546362514225134, 30430660439311103

Offset: 0

Author

Paul Barry, May 21 2005

Keywords

• easy
• nonn

Formula

a(n)=sum{k=0..floor(n/2), sum{j=0..n-2k, C(n-2k+j, 2j)*k^j*C(k)}}, C(n) given by A000108.