A027142 a(n) = Sum_{k=0..2n-2} T(n,k) * T(n,k+2), with T given by A027113.

12, 105, 831, 6648, 53545, 434458, 3548871, 29166324, 241006333, 2001145585, 16688238416, 139711675493, 1173762075101, 9892582661593, 83617537623039, 708654873428000, 6020421349942965, 51261344063828713, 437370998284452284, 3738875265960650016

Offset: 2

Author

Clark Kimberling

Keywords

• nonn

Extensions

More terms from Sean A. Irvine, Oct 23 2019