a(n) is the least k such that the base-10 representation of n begins at s(k), where s=A007376.

Terms

a(0) =1a(1) =2a(2) =3a(3) =4a(4) =5a(5) =6a(6) =7a(7) =8a(8) =9a(9) =10a(10) =12a(11) =1a(12) =16a(13) =18a(14) =20a(15) =22a(16) =24a(17) =26a(18) =28a(19) =30a(20) =15a(21) =34a(22) =2a(23) =38a(24) =40a(25) =42a(26) =44a(27) =46a(28) =48a(29) =50