G.f. satisfies: A( A(x) - 4*A(x)^2 ) = x.

Terms

a(0) =0a(1) =1a(2) =2a(3) =12a(4) =96a(5) =880a(6) =8720a(7) =90752a(8) =975936a(9) =10737152a(10) =120093056a(11) =1360051456a(12) =15556087296a(13) =179424700416