T(n,n+2), array T as in A047040; T(n+2,n), array T given by A047050.

Terms

a(0) =1a(1) =3a(2) =9a(3) =28a(4) =90a(5) =311a(6) =1099a(7) =3928a(8) =14151a(9) =52025a(10) =193192a(11) =721507a(12) =2704857a(13) =10219356a(14) =38814183a(15) =147936398a(16) =565229232a(17) =2167575626a(18) =8337587694a(19) =32144302453a(20) =124143606307a(21) =480449680735