A113140 Diagonal sums of a Delannoy related triangle.

1, 3, 14, 68, 347, 1819, 9712, 52532, 286905, 1578679, 8738278, 48601968, 271406347, 1520725095, 8545396208, 48138689272, 271768537793, 1537212749339, 8709732836238, 49423440297324, 280835252080651, 1597731101233763

Offset: 0

Author

Paul Barry, Oct 15 2005

Keywords

• easy
• nonn

Comments

Diagonal sums of A113139.

Formula

a(n)=sum{k=0..floor(n/2), sum{j=0..n-k, C(n-2k, j)C(n-k+j, k+j)}}.