Ceiling(phi^n) where phi = (1+sqrt(5))/2.

Terms

a(0) =1a(1) =2a(2) =3a(3) =5a(4) =7a(5) =12a(6) =18a(7) =30a(8) =47a(9) =77a(10) =123a(11) =200a(12) =322a(13) =522a(14) =843a(15) =1365a(16) =2207a(17) =3572a(18) =5778a(19) =9350a(20) =15127a(21) =24477a(22) =39603a(23) =64080a(24) =103682a(25) =167762a(26) =271443a(27) =439205a(28) =710647a(29) =1149852