A047031 Sum{T(i,n-i): i=0,1,...,n}, array T as in A047030.

1, 2, 3, 5, 9, 18, 32, 63, 124, 245, 490, 964, 1923, 3835, 7652, 15304, 30504, 60973, 121866, 243596, 487192, 973568, 1946851, 3893037, 7784919, 15569838, 31132592, 62262654, 124519328, 249028126, 498056252, 996046984, 1992070217