A027224 a(n) = Sum_{k=0..n-1} T(n,k) * T(n,k+1), with T given by A026747.

1, 6, 24, 132, 500, 2728, 10324, 56651, 215323, 1191987, 4549786, 25420734, 97369588, 548884043, 2108335364, 11983465575, 46136052623, 264215445322, 1019173758683, 5876647410170, 22705355331214, 131727633042981, 509673506069905, 2973264727753047, 11518483809430525

Offset

1,2

Links

Table of n, a(n) for n=1..25.

Crossrefs

Sequence in context: A200160 A219622 A052170 * A110707 A047712 A188330

Adjacent sequences: A027221 A027222 A027223 * A027225 A027226 A027227

Keyword

nonn

Author

Clark Kimberling

Extensions

More terms from Sean A. Irvine, Oct 24 2019

Status

approved