T(2n,n), array T as in A047130.

Terms

a(0) =1a(1) =2a(2) =9a(3) =48a(4) =261a(5) =1534a(6) =9319a(7) =56808a(8) =353362a(9) =2227380a(10) =14099553a(11) =89931668a(12) =577292621a(13) =3718701300a(14) =24047442913a(15) =156059054586