a(n) = ceiling(n/tau), where tau = (1+sqrt(5))/2.

Terms

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