G.f. A(x) satisfies: A(x) = 1 + x + x^2 + x^3*A(x)^2.

Terms

a(0) =1a(1) =1a(2) =1a(3) =1a(4) =2a(5) =3a(6) =4a(7) =7a(8) =12a(9) =19a(10) =32a(11) =56a(12) =96a(13) =165a(14) =290a(15) =512a(16) =902a(17) =1601a(18) =2862a(19) =5124a(20) =9198a(21) =16585a(22) =29990a(23) =54336a(24) =98702a(25) =179742a(26) =327942a(27) =599432a(28) =1097756a(29) =2013737