A107112 Row sums of A107111, viewed as a number triangle.

1, 2, 5, 15, 54, 228, 1106, 6069, 37212, 252287, 1873928, 15127191, 131788320, 1231650843, 12283477562, 130137706957, 1458823402224, 17242265101407, 214202486482516, 2789239633559763, 37974772474452740, 539356744121554370

Offset: 0

Author

Paul Barry, May 12 2005

Keywords

• easy
• nonn

Formula

a(n)=sum{k=0..n, sum{j=0..k, binomial((n-k)(k+1), k-j)*binomial(k+j, j)}/(k+1)}