a(n) = (greatest base 9 digit of n) - (least base 9 digit of n).

Terms

a(0) =0a(1) =0a(2) =0a(3) =0a(4) =0a(5) =0a(6) =0a(7) =0a(8) =0a(9) =1a(10) =0a(11) =1a(12) =2a(13) =3a(14) =4a(15) =5a(16) =6a(17) =7a(18) =2a(19) =1a(20) =0a(21) =1a(22) =2a(23) =3a(24) =4a(25) =5a(26) =6a(27) =3a(28) =2a(29) =1