G.f. satisfies: A(x)^3 = A(x^2)^3 + 9*x.

Terms

a(0) =1a(1) =3a(2) =-6a(3) =27a(4) =-141a(5) =819a(6) =-5022a(7) =31968a(8) =-209202a(9) =1398420a(10) =-9505854a(11) =65499759a(12) =-456410943a(13) =3210397173a(14) =-22763553876a(15) =162524220984