T(n,n-2), array T as in A038792.

Terms

a(0) =1a(1) =6a(2) =23a(3) =73a(4) =211a(5) =581a(6) =1560a(7) =4135a(8) =10890a(9) =28590a(10) =74946a(11) =196326a(12) =514123a(13) =1346148a(14) =3524441a(15) =9227311a(16) =24157645a(17) =63245795a(18) =165579930a(19) =433494205a(20) =1134902916a(21) =2971214796a(22) =7778741748a(23) =20365010748a(24) =53316290821a(25) =139583862066