A027248 a(n) = Sum_{k=0..n-1} T(n,k) * T(n,k+1), with T given by A026780.

1, 6, 29, 156, 741, 3958, 19233, 103340, 513829, 2782642, 14111035, 76987001, 396866211, 2179190558, 11387537287, 62869497136, 332264796115, 1842788400972, 9831563838105, 54737178645869, 294362713929617, 1644215891925732, 8902034364734719, 49863044050919951

Offset: 1

Author

Clark Kimberling

Keywords

• nonn

Extensions

More terms from Sean A. Irvine, Oct 26 2019