a(n) = Sum_{k=0..2n-3} T(n,k) * T(n,k+3), with T given by A027023.

A027049

a(n) = Sum_{k=0..2n-3} T(n,k) * T(n,k+3), with T given by A027023.

Terms

    a(0) =16a(1) =120a(2) =952a(3) =7848a(4) =65580a(5) =550476a(6) =4631876a(7) =39047764a(8) =329784608a(9) =2790469092a(10) =23656401612a(11) =200928615160

External references