a(n) is the least k such that s(k) = n, where s = A026362.

Terms

a(0) =1a(1) =3a(2) =4a(3) =5a(4) =6a(5) =8a(6) =9a(7) =11a(8) =12a(9) =14a(10) =15a(11) =17a(12) =18a(13) =19a(14) =20a(15) =22a(16) =23a(17) =25a(18) =26a(19) =27a(20) =28a(21) =30a(22) =31a(23) =33a(24) =34a(25) =35a(26) =36a(27) =38a(28) =39a(29) =41