T(n,n-2), array T as in A054115.

Terms

a(0) =1a(1) =6a(2) =30a(3) =150a(4) =870a(5) =5910a(6) =46230a(7) =409110a(8) =4037910a(9) =43954710a(10) =522956310a(11) =6749977110a(12) =93928268310