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

Terms

a(0) =1a(1) =0a(2) =0a(3) =0a(4) =1a(5) =1a(6) =0a(7) =0a(8) =2a(9) =5a(10) =3a(11) =0a(12) =5a(13) =21a(14) =28a(15) =12a(16) =14a(17) =84a(18) =180a(19) =165a(20) =97a(21) =330a(22) =990a(23) =1430a(24) =1133a(25) =1560a(26) =5005a(27) =10010a(28) =11349a(29) =11193