A097252 Numbers whose set of base 6 digits is {0,5}.

0, 5, 30, 35, 180, 185, 210, 215, 1080, 1085, 1110, 1115, 1260, 1265, 1290, 1295, 6480, 6485, 6510, 6515, 6660, 6665, 6690, 6695, 7560, 7565, 7590, 7595, 7740, 7745, 7770, 7775, 38880, 38885, 38910, 38915, 39060, 39065, 39090, 39095, 39960, 39965

Offset: 0

Author

Ray Chandler, Aug 03 2004

Keywords

• nonn
• base

Comments

n such that there exists a permutation p_1, ..., p_n of 1, ..., n such that i + p_i is a power of 6 for every i.

Links

• Vincenzo Librandi, Table of n, a(n) for n = 0..500

Crossrefs

Cf. A001196, A005823, A007088, A033043, A097251-A097262.

Programs

Magma

[n: n in [0..40000] | Set(IntegerToSequence(n, 6)) subset {0, 5}]; // Vincenzo Librandi, May 25 2012

Mathematica

fQ[n_]:=Union@Join[{0,5},IntegerDigits[n,6]]=={0,5};Select[Range[0,40000],fQ] (* Vincenzo Librandi, May 25 2012 *)
FromDigits[#,6]&/@Tuples[{ 0,5},6] (* Harvey P. Dale, Aug 15 2021 *)

Python

def A079252(n): return 5*int(bin(n)[2:],6) # Chai Wah Wu, Apr 04 2025

Formula

a(n) = 5*A033043(n).

a(2n) = 6*a(n), a(2n+1) = a(2n)+5.