Nialpdromes: digits in base 13 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) =11a(12) =12a(13) =13a(14) =14a(15) =26a(16) =27a(17) =28a(18) =39a(19) =40a(20) =41a(21) =42a(22) =52a(23) =53a(24) =54a(25) =55a(26) =56a(27) =65a(28) =66a(29) =67