a(n) = Sum_{k=0..n-1} T(n,k) * T(n,k+3), with T given by A026323.
A027311
a(n) = Sum_{k=0..n-1} T(n,k) * T(n,k+3), with T given by A026323.
Terms
- a(0) =4a(1) =43a(2) =396a(3) =3465a(4) =29730a(5) =253008a(6) =2145968a(7) =18184052a(8) =154119660a(9) =1307389666a(10) =11104039000a(11) =94441581936a(12) =804428517984
External references
- oeis: A027311