A027249 a(n) = Sum_{k=0..n-2} T(n,k) * T(n,k+2), with T given by A026780.

1, 9, 59, 338, 1937, 10289, 57345, 299832, 1663421, 8705069, 48391863, 254818488, 1421911953, 7544528179, 42264280735, 225949128338, 1270219491983, 6838142459779, 38557301241769, 208865221891584, 1180647902778713, 6430734346787925, 36426544777112515, 199364753897943071

Offset: 2

Author

Clark Kimberling

Keywords

• nonn

Extensions

More terms from Sean A. Irvine, Oct 26 2019