A023753 Plaindromes: numbers whose digits in base 12 are in nondecreasing order.

0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 39, 40, 41, 42, 43, 44, 45, 46, 47, 52, 53, 54, 55, 56, 57, 58, 59, 65, 66, 67, 68, 69, 70, 71, 78, 79, 80, 81, 82, 83, 91, 92, 93, 94, 95, 104

Offset: 1

Author

Olivier Gérard

Keywords

• nonn
• base
• easy

Links

• Vincenzo Librandi, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A000225, A023745, ..., A023757 (nondecreasing digits in base 2, 3, ..., 16).

Cf. A023758, A023759, ..., A023771 (nonincreasing digits in base 2, 3, ..., 16).

Programs

Mathematica

Select[Range[0,104],LessEqual@@IntegerDigits[#,12]&] (* Ray Chandler, Jan 06 2014 *)
Select[Range[0,120],Min[Differences[IntegerDigits[#,12]]]>-1&] (* Harvey P. Dale, Jul 10 2023 *)

PARI

is(n)=vecsort(n=digits(n,12))==n
for(n=0,2,forvec(d=vector(n,i,[1,11]),print1(fromdigits(d,12)","),1)) \\ M. F. Hasler, May 05 2020

Python

from itertools import count, islice, combinations_with_replacement
def A023753_gen(): # generator of terms
    yield 0
    yield from (int(''.join(c),12) for l in count(1) for c in combinations_with_replacement('123456789ab',l))
A023753_list = list(islice(A023753_gen(),30)) # Chai Wah Wu, Apr 08 2025

Extensions

Change offset to 1 by Ray Chandler, Jan 06 2014