If d,e are consecutive digits of n in base 8, then |d-e|>=4.

Terms

a(0) =1a(1) =2a(2) =3a(3) =4a(4) =5a(5) =6a(6) =7a(7) =13a(8) =14a(9) =15a(10) =22a(11) =23a(12) =31a(13) =32a(14) =40a(15) =41a(16) =48a(17) =49a(18) =50a(19) =56a(20) =57a(21) =58a(22) =59a(23) =104a(24) =105a(25) =112a(26) =113a(27) =114a(28) =120a(29) =121