G.f. A(x) satisfies: A(x) = 1 / (1 + x) + x * (1 + x) * A(x)^3.

Terms

a(0) =1a(1) =0a(2) =2a(3) =5a(4) =22a(5) =92a(6) =415a(7) =1927a(8) =9198a(9) =44804a(10) =221880a(11) =1113730a(12) =5653747a(13) =28975962a(14) =149725355a(15) =779178092a(16) =4080167790a(17) =21483383992a(18) =113670233848a(19) =604070682354