A023765 Nialpdromes: digits in base 9 are in nonincreasing order.

0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 18, 19, 20, 27, 28, 29, 30, 36, 37, 38, 39, 40, 45, 46, 47, 48, 49, 50, 54, 55, 56, 57, 58, 59, 60, 63, 64, 65, 66, 67, 68, 69, 70, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 90, 91, 162, 171, 172, 180, 181, 182, 243, 252, 253, 261

Offset

1,3

Links

Vincenzo Librandi, Table of n, a(n) for n = 1..1000

Example

From Michael De Vlieger, Oct 17 2018: (Start)
10 is in the sequence because 10 in base 9 is "11"; these digits are nondecreasing.
12 is not in the sequence because its base-9 digits "13" increase. (End)

Mathematica

Select[Range[0, 2000], Max[Differences[IntegerDigits[#, 9]]]<=0&] (* Vincenzo Librandi, Dec 26 2012 *)
Select[Range[0, 261], GreaterEqual@@IntegerDigits[#, 9]&] (* Ray Chandler, Jan 06 2014 *)
Select[Range@ 200, AllTrue[Differences@ IntegerDigits[#, 9], # <= 0 &] &] (* Michael De Vlieger, Oct 17 2018 *)

Crossrefs

Sequence in context: A347295 A032872 A032345 * A032906 A349484 A075905

Adjacent sequences: A023762 A023763 A023764 * A023766 A023767 A023768

Keyword

nonn,base,easy

Author

Olivier Gérard

Status

approved