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

Terms

a(0) =1a(1) =1a(2) =3a(3) =7a(4) =19a(5) =54a(6) =161a(7) =492a(8) =1532a(9) =4843a(10) =15503a(11) =50159a(12) =163782a(13) =539050a(14) =1786432a(15) =5956195a(16) =19965072a(17) =67241547a(18) =227433663a(19) =772217118a(20) =2631085326a(21) =8993020595a(22) =30827136777a(23) =105953214815a(24) =365054019536