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

Terms

a(0) =1a(1) =1a(2) =1a(3) =1a(4) =2a(5) =7a(6) =23a(7) =65a(8) =167a(9) =418a(10) =1078a(11) =2927a(12) =8261a(13) =23677a(14) =67917a(15) =194401a(16) =557097a(17) =1604805a(18) =4655373a(19) =13592002a(20) =39875297a(21) =117379888a(22) =346445156a(23) =1025077295a(24) =3040774879a(25) =9043131251a(26) =26958950829a(27) =80545589421a(28) =241122613367a(29) =723125785251