A Beatty sequence: floor(n * (sqrt(5) - 1)).

Terms

a(0) =1a(1) =2a(2) =3a(3) =4a(4) =6a(5) =7a(6) =8a(7) =9a(8) =11a(9) =12a(10) =13a(11) =14a(12) =16a(13) =17a(14) =18a(15) =19a(16) =21a(17) =22a(18) =23a(19) =24a(20) =25a(21) =27a(22) =28a(23) =29a(24) =30a(25) =32a(26) =33a(27) =34a(28) =35a(29) =37