Expansion of A(x) satisfying A(A(x)) = x+2x^2+4x^3.

Terms

a(0) =1a(1) =1a(2) =1a(3) =-3a(4) =5a(5) =1a(6) =-39a(7) =117a(8) =13a(9) =-1311a(10) =3441a(11) =9525a(12) =-78603a(13) =16961a(14) =1520521a(15) =-3649323a(16) =-28760163a(17) =144787265a(18) =601582689a(19) =-5374096875a(20) =-15170850555a(21) =225456060897a(22) =461284881657