T(2n,n), array T as in A047060.

Terms

a(0) =1a(1) =2a(2) =9a(3) =50a(4) =292a(5) =1757a(6) =10809a(7) =67473a(8) =425711a(9) =2707757a(10) =17332058a(11) =111508304a(12) =720429774a(13) =4670990039a(14) =30375989547a(15) =198050065342