A043539 - OEIS

%I #14 Apr 24 2021 21:30:21

%S 1,1,1,1,1,1,1,1,1,1,1,2,1,2,2,2,2,2,2,2,2,2,2,2,2,1,2,2,2,2,2,2,2,2,

%T 2,2,2,2,1,2,2,2,2,2,2,2,2,2,2,2,2,1,2,2,2,2,2,2,2,2,2,2,2,2,1,2,2,2,

%U 2,2,2,2,2,2,2,2,2,1,2,2,2,2,2,2,2,2,2,2,2,2

%N Number of distinct base-12 digits of n.

%H Vincenzo Librandi, <a href="/A043539/b043539.txt">Table of n, a(n) for n = 1..5000</a>

%F From _Michael De Vlieger_, Aug 14 2017: (Start)

%F a(11) = 1 since 11 in base 12 is written with a single digit.

%F a(13) = 1 since 13 in base 12 is written "11".

%F a(14) = 2 since 14 in base 12 is written "12".

%F a(146) is the first appearance of 3 in this sequence, since it is written "102" in base 12.

%F (End)

%t Table[Length[Select[DigitCount[n, 12], #>0&]], {n, 100}] (* _Vincenzo Librandi_, Aug 13 2017 *)

%o (PARI) a(n) = #Set(digits(n, 12)); \\ _Michel Marcus_, Aug 13 2017

%K nonn,base

%O 1,12

%A _Clark Kimberling_