A027234 a(n) = Sum_{k=0..n-3} T(n,k) * T(n,k+3), with T given by A026758.

1, 9, 62, 320, 1837, 8376, 45666, 198471, 1065418, 4523403, 24247545, 101589616, 547233490, 2273356598, 12341618508, 50963502172, 279167141052, 1147495086055, 6344204700832, 25979651242434, 144938080884808, 591635283209270, 3328970814605391, 13551109648829458, 76853618775913752

Offset: 3

Author

Clark Kimberling

Keywords

• nonn

Extensions

More terms from Sean A. Irvine, Oct 24 2019