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

Terms

a(0) =1a(1) =1a(2) =1a(3) =2a(4) =3a(5) =6a(6) =10a(7) =21a(8) =40a(9) =85a(10) =170a(11) =362a(12) =752a(13) =1618a(14) =3438a(15) =7447a(16) =16065a(17) =35080a(18) =76574a(19) =168424a(20) =370880a(21) =820968a(22) =1820598a(23) =4052594a(24) =9038457a(25) =20216002a(26) =45301380a(27) =101746560a(28) =228918438a(29) =516016266