a(n) = 2*n/3 for n divisible by 3, otherwise a(n) = round(4*n/3). Or, equivalently, a(3*n-2) = 4*n-3, a(3*n-1) = 4*n-1, a(3*n) = 2*n.

A006369

a(n) = 2*n/3 for n divisible by 3, otherwise a(n) = round(4*n/3). Or, equivalently, a(3*n-2) = 4*n-3, a(3*n-1) = 4*n-1, a(3*n) = 2*n.

Terms

    a(0) =0a(1) =1a(2) =3a(3) =2a(4) =5a(5) =7a(6) =4a(7) =9a(8) =11a(9) =6a(10) =13a(11) =15a(12) =8a(13) =17a(14) =19a(15) =10a(16) =21a(17) =23a(18) =12a(19) =25a(20) =27a(21) =14a(22) =29a(23) =31a(24) =16a(25) =33a(26) =35a(27) =18a(28) =37a(29) =39

External references