a(n) = floor((1 + 2^n)/(1 + 2*n)).

Terms

a(0) =1a(1) =1a(2) =1a(3) =1a(4) =3a(5) =5a(6) =8a(7) =15a(8) =27a(9) =48a(10) =89a(11) =163a(12) =303a(13) =565a(14) =1057a(15) =1985a(16) =3744a(17) =7085a(18) =13443a(19) =25575a(20) =48771a(21) =93206a(22) =178481a(23) =342392a(24) =657930a(25) =1266205a(26) =2440322a(27) =4709393a(28) =9099507a(29) =17602325