T(n,n-2), array T as in A054090.

Terms

a(0) =1a(1) =4a(2) =6a(3) =26a(4) =104a(5) =548a(6) =3366a(7) =24034a(8) =195168a(9) =1777652a(10) =17950550a(11) =199059674a(12) =2405063016a(13) =31448531956a(14) =442501797654