Least k such that s(k) = n, where s = A026342.

Terms

a(0) =1a(1) =3a(2) =4a(3) =7a(4) =8a(5) =9a(6) =10a(7) =13a(8) =16a(9) =17a(10) =18a(11) =19a(12) =21a(13) =22a(14) =23a(15) =25a(16) =28a(17) =30a(18) =31a(19) =34a(20) =36a(21) =37a(22) =39a(23) =40a(24) =41a(25) =43a(26) =44a(27) =46a(28) =48a(29) =49