T(n,n-2), array T as in A047089.

Terms

a(0) =1a(1) =3a(2) =8a(3) =19a(4) =98a(5) =335a(6) =1381a(7) =5164a(8) =20306a(9) =77915a(10) =303445a(11) =1175121a(12) =4574312a(13) =17794125a(14) =69379714a(15) =270671995a(16) =1057440462a(17) =4134573755a(18) =16182570293a(19) =63389522371a(20) =248511714532a(21) =974976349772