G.f. satisfies A(x) = x * Product_{n>=0} (1 + A(x)^(2^n))^(2^n).

Terms

a(0) =1a(1) =1a(2) =3a(3) =9a(4) =34a(5) =131a(6) =536a(7) =2249a(8) =9701a(9) =42622a(10) =190308a(11) =860603a(12) =3934296a(13) =18151028a(14) =84404420a(15) =395188265a(16) =1861465438a(17) =8814848613a(18) =41940308252a(19) =200397301502a(20) =961200513274