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

Terms

a(0) =1a(1) =0a(2) =-1a(3) =-1a(4) =1a(5) =4a(6) =3a(7) =-8a(8) =-23a(9) =-10a(10) =67a(11) =153a(12) =9a(13) =-586a(14) =-1081a(15) =439a(16) =5249a(17) =7734a(18) =-7941a(19) =-47501a(20) =-53791a(21) =105314a(22) =430119a(23) =343044a(24) =-1249799a(25) =-3866556a(26) =-1730017a(27) =13996097a(28) =34243897a(29) =1947204