a(n) = Sum_{k=0..n-2} T(n,k) * T(n,k+2), with T given by A026747.
A027225
a(n) = Sum_{k=0..n-2} T(n,k) * T(n,k+2), with T given by A026747.
Terms
- a(0) =1a(1) =8a(2) =52a(3) =247a(4) =1416a(5) =6056a(6) =33731a(7) =139016a(8) =770116a(9) =3121259a(10) =17335095a(11) =69642995a(12) =388958218a(13) =1554558921a(14) =8740670953a(15) =34818606079a(16) =197136480944a(17) =783522002716
External references
- oeis: A027225