T(n,n-1), array T given by A047020.

Terms

a(0) =1a(1) =1a(2) =4a(3) =5a(4) =19a(5) =66a(6) =293a(7) =1144a(8) =4308a(9) =17158a(10) =67007a(11) =258431a(12) =1012299a(13) =3955448a(14) =15396192a(15) =60225003a(16) =235693679a(17) =921621773a(18) =3610690891a(19) =14157362951a(20) =55517613242a(21) =217923561656a(22) =856025426013