a(n) = Sum_{k=0..2n-3} T(n,k) * T(n,k+3), with T given by A026536.
A027270
a(n) = Sum_{k=0..2n-3} T(n,k) * T(n,k+3), with T given by A026536.
Terms
- a(0) =2a(1) =10a(2) =104a(3) =420a(4) =3786a(5) =14826a(6) =131264a(7) =510576a(8) =4508580a(9) =17523506a(10) =154773696a(11) =602175444a(12) =5323519838a(13) =20744201142a(14) =183586707648a(15) =716553432640
External references
- oeis: A027270