T(n,n-2), array T as in A047110.

Terms

a(0) =1a(1) =3a(2) =9a(3) =24a(4) =73a(5) =164a(6) =534a(7) =3187a(8) =11000a(9) =39888a(10) =174411a(11) =665360a(12) =2528518a(13) =10223830a(14) =39909056a(15) =154727890a(16) =612630675a(17) =2404810575a(18) =9405235895a(19) =37053238445a(20) =145729990271a(21) =572330060383