If d,e are consecutive digits of n in base 10, then |d-e|>=4.

Terms

a(0) =1a(1) =2a(2) =3a(3) =4a(4) =5a(5) =6a(6) =7a(7) =8a(8) =9a(9) =15a(10) =16a(11) =17a(12) =18a(13) =19a(14) =26a(15) =27a(16) =28a(17) =29a(18) =37a(19) =38a(20) =39a(21) =40a(22) =48a(23) =49a(24) =50a(25) =51a(26) =59a(27) =60a(28) =61a(29) =62