T(n,n-1), array T given by A047000.

Terms

a(0) =1a(1) =2a(2) =2a(3) =7a(4) =30a(5) =113a(6) =442a(7) =1692a(8) =6542a(9) =25213a(10) =97548a(11) =377617a(12) =1465010a(13) =5690787a(14) =22140830a(15) =86250091a(16) =336416094a(17) =1313641661a(18) =5134950280a(19) =20091508863a(20) =78682553016a(21) =308392187964