A039268 Numbers whose base-12 representation has the same number of 7's and 11's.

0, 1, 2, 3, 4, 5, 6, 8, 9, 10, 12, 13, 14, 15, 16, 17, 18, 20, 21, 22, 24, 25, 26, 27, 28, 29, 30, 32, 33, 34, 36, 37, 38, 39, 40, 41, 42, 44, 45, 46, 48, 49, 50, 51, 52, 53, 54, 56, 57, 58, 60, 61, 62, 63, 64, 65, 66, 68, 69, 70, 72, 73, 74, 75, 76, 77, 78, 80

Offset: 1

Author

Olivier Gérard

Keywords

• nonn
• base
• easy

Links

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

Programs

Magma

[n: n in [0..100] | Multiplicity(S,7) eq Multiplicity(S,11) where S is {*d: d in Intseq(n,12)*}]; // Bruno Berselli, Oct 20 2012

Mathematica

Select[Range[0, 100], DigitCount[#, 12, 7] == DigitCount[#, 12, 11] &] (* Vincenzo Librandi, Oct 20 2012 *)

Extensions

An incorrect g.f. was deleted by N. J. A. Sloane, Sep 13 2009