a(n) = Sum_{k=0..2n-2} T(n,k) * T(n,k+2), with T given by A026568.

A027279

a(n) = Sum_{k=0..2n-2} T(n,k) * T(n,k+2), with T given by A026568.

Terms

    a(0) =7a(1) =44a(2) =273a(3) =1696a(4) =10573a(5) =66151a(6) =415277a(7) =2615004a(8) =16512355a(9) =104526093a(10) =663143211a(11) =4215574482a(12) =26846320149a(13) =171243444982

External references