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

Terms

a(0) =1a(1) =1a(2) =1a(3) =1a(4) =2a(5) =3a(6) =5a(7) =8a(8) =13a(9) =21a(10) =35a(11) =57a(12) =94a(13) =154a(14) =254a(15) =417a(16) =687a(17) =1129a(18) =1859a(19) =3057a(20) =5032a(21) =8277a(22) =13623a(23) =22412a(24) =36883a(25) =60684a(26) =99862a(27) =164312a(28) =270384a(29) =444899