T(n,n-3), array T as in A047100.

Terms

a(0) =1a(1) =3a(2) =5a(3) =31a(4) =120a(5) =491a(6) =2016a(7) =8039a(8) =31884a(9) =126281a(10) =498558a(11) =1965077a(12) =7740246a(13) =30473582a(14) =119948507a(15) =472129697a(16) =1858535320a(17) =7317392228a(18) =28816569762a(19) =113512547183a(20) =447270667394