A110137 Diagonal sums of A110135 when read as a number triangle.

1, 2, 7, 22, 79, 286, 1071, 4070, 15721, 61506, 243703, 977366, 3968169, 16313842, 67942539, 286769518, 1227194947, 5326324598, 23451408843, 104753097326, 474663076539, 2181355670806, 10163422480887, 47988508807190

Offset

0,2

Links

Table of n, a(n) for n=0..23.

Formula

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

Crossrefs

Sequence in context: A176612 A132838 A047095 * A097967 A360861 A052879

Adjacent sequences: A110134 A110135 A110136 * A110138 A110139 A110140

Keyword

easy,nonn

Author

Paul Barry, Jul 13 2005

Status

approved