A037440 Positive numbers having the same set of digits in base 7 and base 10.

1, 2, 3, 4, 5, 6, 23, 46, 265, 316, 1030, 1234, 1336, 1366, 1401, 1431, 1443, 1454, 1464, 2060, 2116, 3261, 3515, 3621, 4631, 5052, 10144, 10342, 10542, 11134, 11425, 11524, 11544, 12415, 12450, 12532, 12564, 12651, 13035, 13045, 13245

Offset

1,2

Links

John Cerkan, Table of n, a(n) for n = 1..10000

Example

1336 is in the sequence because 1336 in base 7 is 3616.

Mathematica

Select[Range@ 13300, Union@ IntegerDigits@ # == Union@ IntegerDigits[#, 7] &] (* Michael De Vlieger, Feb 18 2017 *)

Prog

(PARI) isok(n) = Set(digits(n, 7)) == Set(digits(n)); \\ Michel Marcus, Feb 18 2017
(Python)
from sympy.ntheory import digits
def ok(n): return set(map(int, str(n))) == set(digits(n, 7)[1:])
print([k for k in range(1, 10**6) if ok(k)]) # Michael S. Branicky, Apr 22 2023

Crossrefs

Subsequence of A037404.

Cf. A007093.

Sequence in context: A183529 A342999 A037404 * A130604 A359224 A262434

Adjacent sequences: A037437 A037438 A037439 * A037441 A037442 A037443

Keyword

nonn,base

Author

Clark Kimberling

Extensions

More terms from Don Reble, Apr 28 2006

Edited by John Cerkan, Feb 17 2017

Status

approved