Nialpdromes: digits in base 9 are in nonincreasing order.

Terms

a(0) =0a(1) =1a(2) =2a(3) =3a(4) =4a(5) =5a(6) =6a(7) =7a(8) =8a(9) =9a(10) =10a(11) =18a(12) =19a(13) =20a(14) =27a(15) =28a(16) =29a(17) =30a(18) =36a(19) =37a(20) =38a(21) =39a(22) =40a(23) =45a(24) =46a(25) =47a(26) =48a(27) =49a(28) =50a(29) =54