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

Author

Clark Kimberling

Keywords

• nonn

Extensions

More terms from Sean A. Irvine, Oct 24 2019