G.f. A(x) satisfies: 1 = Sum_{n=-oo..+oo} (x^n - 2*x*A(x))^n.

Terms

a(0) =1a(1) =2a(2) =3a(3) =3a(4) =5a(5) =39a(6) =206a(7) =697a(8) =1656a(9) =3208a(10) =8727a(11) =41667a(12) =192142a(13) =688944a(14) =1965643a(15) =5117374a(16) =15888133a(17) =63924038a(18) =263759291a(19) =955198539a(20) =3017571957a(21) =9101208987a(22) =30075674452a(23) =113177783141a(24) =437460265979