G.f. A(x) satisfies: 1-x = Sum_{n>=0} (A(x) + (-x)^n)^n * (-x)^n.

Terms

a(0) =1a(1) =2a(2) =3a(3) =7a(4) =16a(5) =41a(6) =107a(7) =286a(8) =782a(9) =2179a(10) =6172a(11) =17702a(12) =51272a(13) =149727a(14) =440341a(15) =1303130a(16) =3877837a(17) =11596602a(18) =34832573a(19) =105041452a(20) =317900632a(21) =965240836a(22) =2939479066a(23) =8976098663a(24) =27478467863a(25) =84314278171a(26) =259262013763a(27) =798802232031