Expansion of solution of functional equation.

Terms

a(0) =1a(1) =1a(2) =1a(3) =1a(4) =1a(5) =2a(6) =5a(7) =11a(8) =21a(9) =37a(10) =66a(11) =127a(12) =261a(13) =545a(14) =1119a(15) =2255a(16) =4529a(17) =9202a(18) =18989a(19) =39566a(20) =82614a(21) =172272a(22) =359159a(23) =750699a(24) =1575649a(25) =3319942a(26) =7012833a(27) =14834345a(28) =31414423a(29) =66619692