a(n) = Sum_{k=0..n} T(n,k) * T(n,k+2), with T given by A026323.

A027310

a(n) = Sum_{k=0..n} T(n,k) * T(n,k+2), with T given by A026323.

Terms

    a(0) =1a(1) =10a(2) =84a(3) =691a(4) =5625a(5) =45891a(6) =375627a(7) =3087869a(8) =25492266a(9) =211320955a(10) =1758522205a(11) =14686149360a(12) =123057387973

External references