T(n,n-2), array T as in A047130.

Terms

a(0) =1a(1) =3a(2) =9a(3) =28a(4) =76a(5) =235a(6) =768a(7) =1679a(8) =5564a(9) =19613a(10) =126070a(11) =437604a(12) =1610354a(13) =6015427a(14) =27167487a(15) =104861750a(16) =403189070a(17) =1550582656a(18) =6369655714a(19) =25112303442a(20) =98241919002a(21) =383342448413