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

0,2

Links

Table of n, a(n) for n=0..21.

Formula

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

Crossrefs

Sequence in context: A369599 A208237 A321958 * A193318 A171450 A204190

Adjacent sequences: A107109 A107110 A107111 * A107113 A107114 A107115

Keyword

easy,nonn

Author

Paul Barry, May 12 2005

Status

approved