a(n) = Sum_{k=0..2n-1} T(n,k) * T(n,k+1), with T given by A027023.
A027047
a(n) = Sum_{k=0..2n-1} T(n,k) * T(n,k+1), with T given by A027023.
Terms
- a(0) =2a(1) =8a(2) =50a(3) =336a(4) =2418a(5) =18088a(6) =138850a(7) =1086016a(8) =8617122a(9) =69159896a(10) =560290322a(11) =4574820624a(12) =37603654098a(13) =310873702392
External references
- oeis: A027047