Katadromes: digits in base 8 are in strict descending order.

Terms

a(0) =0a(1) =1a(2) =2a(3) =3a(4) =4a(5) =5a(6) =6a(7) =7a(8) =8a(9) =16a(10) =17a(11) =24a(12) =25a(13) =26a(14) =32a(15) =33a(16) =34a(17) =35a(18) =40a(19) =41a(20) =42a(21) =43a(22) =44a(23) =48a(24) =49a(25) =50a(26) =51a(27) =52a(28) =53a(29) =56