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

Terms

a(0) =1a(1) =1a(2) =0a(3) =0a(4) =1a(5) =0a(6) =-1a(7) =1a(8) =0a(9) =-2a(10) =3a(11) =0a(12) =-6a(13) =10a(14) =0a(15) =-22a(16) =33a(17) =0a(18) =-79a(19) =122a(20) =0a(21) =-299a(22) =472a(23) =0a(24) =-1179a(25) =1871a(26) =0a(27) =-4754a(28) =7601a(29) =0