G.f. A(x) satisfies A(x) = 1 + x^4 * (A(x) / (1 - x))^2.

Terms

a(0) =1a(1) =0a(2) =0a(3) =0a(4) =1a(5) =2a(6) =3a(7) =4a(8) =7a(9) =14a(10) =27a(11) =48a(12) =84a(13) =152a(14) =284a(15) =532a(16) =987a(17) =1826a(18) =3401a(19) =6384a(20) =12024a(21) =22656a(22) =42728a(23) =80780a(24) =153151a(25) =290970a(26) =553601a(27) =1054688a(28) =2012373a(29) =3845646