A027225 a(n) = Sum_{k=0..n-2} T(n,k) * T(n,k+2), with T given by A026747.

1, 8, 52, 247, 1416, 6056, 33731, 139016, 770116, 3121259, 17335095, 69642995, 388958218, 1554558921, 8740670953, 34818606079, 197136480944, 783522002716, 4466326137854, 17722654061673, 101674164224552, 402960855102206, 2325563749837462, 9208279020729297, 53433859702165884

Offset: 2

Author

Clark Kimberling

Keywords

• nonn

Extensions

More terms from Sean A. Irvine, Oct 24 2019