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

Terms

a(0) =1a(1) =0a(2) =0a(3) =0a(4) =1a(5) =1a(6) =0a(7) =0a(8) =2a(9) =4a(10) =2a(11) =0a(12) =5a(13) =15a(14) =15a(15) =5a(16) =14a(17) =56a(18) =84a(19) =56a(20) =56a(21) =210a(22) =420a(23) =420a(24) =342a(25) =834a(26) =1980a(27) =2640a(28) =2409a(29) =3795