G.f. satisfies A(x) = A( x^3 + x^3*A(x) ) / x^2.

Terms

a(0) =1a(1) =1a(2) =1a(3) =2a(4) =4a(5) =7a(6) =12a(7) =22a(8) =42a(9) =81a(10) =157a(11) =307a(12) =606a(13) =1206a(14) =2416a(15) =4865a(16) =9839a(17) =19981a(18) =40737a(19) =83343a(20) =171028a(21) =351940a(22) =726099a(23) =1501642a(24) =3112400a(25) =6464125a(26) =13450825a(27) =28038767a(28) =58544953a(29) =122431896