a(n) = (s(n) + 1)/2, where s(n) is the n-th odd number in A026234.

Terms

a(0) =1a(1) =2a(2) =3a(3) =4a(4) =6a(5) =7a(6) =5a(7) =9a(8) =10a(9) =12a(10) =15a(11) =16a(12) =19a(13) =21a(14) =22a(15) =8a(16) =24a(17) =27a(18) =30a(19) =31a(20) =34a(21) =36a(22) =37a(23) =40a(24) =42a(25) =45a(26) =49a(27) =51a(28) =52a(29) =54