T(n,n-3), array T as in A047150.

Terms

a(0) =1a(1) =5a(2) =19a(3) =72a(4) =268a(5) =1005a(6) =3799a(7) =14350a(8) =54444a(9) =207135a(10) =790949a(11) =3031433a(12) =11646994a(13) =44857634a(14) =173127114a(15) =669509099a(16) =2594004566a(17) =10066946714a(18) =39126828963a(19) =152278248462a(20) =593391659312