Index of n-th 1 in A006928.

Terms

a(0) =1a(1) =3a(2) =4a(3) =6a(4) =9a(5) =12a(6) =13a(7) =15a(8) =16a(9) =19a(10) =21a(11) =22a(12) =24a(13) =27a(14) =28a(15) =30a(16) =31a(17) =33a(18) =36a(19) =39a(20) =40a(21) =42a(22) =45a(23) =47a(24) =48a(25) =50a(26) =51a(27) =54a(28) =57a(29) =58