A027296 a(n) = Sum_{k=0..floor((n-1)/2)} T(n,k) * T(n,k+2), with T given by A026022.

1, 6, 22, 100, 345, 1470, 5096, 21120, 74175, 302698, 1076922, 4352140, 15660827, 62876490, 228468272, 913093664, 3345466023, 13326904266, 49176362780, 195434713432, 725586231766, 2878605745972, 10744342665072, 42571577779200, 159638882959595, 631933882236306

Offset: 2

Author

Clark Kimberling

Keywords

• nonn

Crossrefs

Cf. A026022.

Extensions

More terms from Sean A. Irvine, Oct 26 2019