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

Terms

a(0) =1a(1) =1a(2) =3a(3) =8a(4) =25a(5) =57a(6) =22a(7) =-1003a(8) =-9967a(9) =-67627a(10) =-394013a(11) =-1958808a(12) =-7869346a(13) =-17261270a(14) =104411359a(15) =1931214493a(16) =19188604691a(17) =153913872501