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

Terms

a(0) =1a(1) =1a(2) =3a(3) =2a(4) =9a(5) =7a(6) =17a(7) =10a(8) =41a(9) =31a(10) =75a(11) =44a(12) =150a(13) =106a(14) =238a(15) =132a(16) =445a(17) =313a(18) =711a(19) =398a(20) =1251a(21) =853a(22) =1859a(23) =1006a(24) =3135a(25) =2129a(26) =4677a(27) =2548a(28) =7590a(29) =5042