If d,e are consecutive digits of n in base 9, then |d-e|>=5.

Terms

a(0) =1a(1) =2a(2) =3a(3) =4a(4) =5a(5) =6a(6) =7a(7) =8a(8) =15a(9) =16a(10) =17a(11) =25a(12) =26a(13) =35a(14) =45a(15) =54a(16) =55a(17) =63a(18) =64a(19) =65a(20) =72a(21) =73a(22) =74a(23) =75a(24) =135a(25) =136a(26) =144a(27) =145a(28) =146a(29) =153