A023804 Xenodromes: all digits in base 9 are different.

0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 11, 12, 13, 14, 15, 16, 17, 18, 19, 21, 22, 23, 24, 25, 26, 27, 28, 29, 31, 32, 33, 34, 35, 36, 37, 38, 39, 41, 42, 43, 44, 45, 46, 47, 48, 49, 51, 52, 53, 54, 55, 56, 57, 58, 59, 61, 62, 63, 64, 65, 66, 67, 68, 69, 71, 72, 73, 74, 75

Offset

1,3

Comments

Last term is a(876809) = 381367044. - Charles R Greathouse IV, Jun 16 2012

Links

Michael De Vlieger, Table of n, a(n) for n = 1..10000

Michael De Vlieger, Extended b-file style table of all terms

Example

From Michael De Vlieger, Mar 24 2021: (Start)
Numbers 0 through 8 are in the sequence because these are single digits in base 9 (nonary).
9 is in the sequence because 9 = "10" in base 9, and both nonary digits are distinct.
11 is in the sequence because, though in decimal the number repeats the digit 1, in base 9, 11 is written "13", with 2 distinct digits.
(End)

Mathematica

Select[Range[0, 80], Max[DigitCount[#, 9]]==1&]  (* Harvey P. Dale, Apr 26 2011 *)
(* Second program: generate all terms (less than a second): *)
Union@ Flatten@ Map[FromDigits[#, 9] & /@ Permutations[-1 + Position[Reverse@ #, 1][[All, 1]] ] &, IntegerDigits[Range[2, 2^9] - 1, 2] ] (* Michael De Vlieger, Mar 24 2021 *)

Prog

(Python)
from itertools import permutations
A023804_list = sorted(set(int(''.join(d), 9) for k in range(1, 10) for d in permutations('012345678', k))) # Chai Wah Wu, Mar 25 2021

Crossrefs

Sequence in context: A171397 A336557 A335235 * A342851 A067251 A209931

Adjacent sequences: A023801 A023802 A023803 * A023805 A023806 A023807

Keyword

nonn,base,fini,easy

Author

Olivier Gérard

Status

approved