G.f. A(x) satisfies A(x) = 1 - x/A(x)^2 * (1 - A(x) - A(x)^3).

Terms

a(0) =1a(1) =1a(2) =2a(3) =2a(4) =-1a(5) =-4a(6) =7a(7) =33a(8) =-5a(9) =-200a(10) =-151a(11) =1185a(12) =2202a(13) =-6069a(14) =-21799a(15) =21791a(16) =182718a(17) =26520a(18) =-1349611a(19) =-1613331a(20) =8674338a(21) =21651795a(22) =-44750412a(23) =-217666394a(24) =121538304a(25) =1859974399a(26) =1023915107a(27) =-13828122997a(28) =-23155237537a(29) =86925632115