T(2n,n), array T as in A047110.

Terms

a(0) =1a(1) =2a(2) =9a(3) =44a(4) =250a(5) =1418a(6) =8567a(7) =51635a(8) =321039a(9) =1996724a(10) =12628528a(11) =80011583a(12) =511889348a(13) =3282172599a(14) =21172582733a(15) =136879748346a(16) =888481523846