G.f. A(x) satisfies A(x) = ( 1 + 9*x*A(x)*(1 + x*A(x)) )^(1/3).

Terms

a(0) =1a(1) =3a(2) =3a(3) =0a(4) =9a(5) =0a(6) =-63a(7) =189a(8) =0a(9) =-1944a(10) =6399a(11) =0a(12) =-72009a(13) =245430a(14) =0a(15) =-2921832a(16) =10184130a(17) =0a(18) =-125775585a(19) =445134690a(20) =0a(21) =-5641620192a(22) =20188568790a(23) =0a(24) =-260832419406a(25) =941254831539a(26) =0a(29) =0a(32) =0