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

Terms

a(0) =1a(1) =3a(2) =9a(3) =33a(4) =115a(5) =401a(6) =1482a(7) =5449a(8) =20048a(9) =75303a(10) =283599a(11) =1069860a(12) =4070772a(13) =15539326a(14) =59433763a(15) =228278533a(16) =879053987a(17) =3391075968a(18) =13113667186a(19) =50808921375a(20) =197150760045a(21) =766241841810