Numbers with the property that all pairs of consecutive base-7 digits differ by 0 or 1.

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) =23a(13) =24a(14) =25a(15) =31a(16) =32a(17) =33a(18) =39a(19) =40a(20) =41a(21) =47a(22) =48a(23) =49a(24) =50a(25) =56a(26) =57a(27) =58a(28) =64a(29) =65