T(n,n+3), array T as in A047060.

Terms

a(0) =1a(1) =3a(2) =7a(3) =12a(4) =30a(5) =99a(6) =476a(7) =1966a(8) =9690a(9) =41343a(10) =177545a(11) =735854a(12) =2982553a(13) =12147231a(14) =49062103a(15) =197792469a(16) =794236626a(17) =3176408470a(18) =12689052371a(19) =50613185496a(20) =201709743301a(21) =803183013778