T(2n,n), array T as in A054126.

Terms

a(0) =2a(1) =5a(2) =24a(3) =134a(4) =802a(5) =4960a(6) =31212a(7) =198504a(8) =1271754a(9) =8192780a(10) =53009614a(11) =344213930a(12) =2241814696a(13) =14637778784a(14) =95786210880