A007734 - OEIS

%I #21 Feb 13 2014 13:17:12

%S 1,1,1,2,4,1,6,2,1,4,5,2,3,6,4,4,16,1,18,4,6,5,11,2,20,3,1,6,28,4,30,

%T 8,5,16,12,2,18,18,3,4,8,6,42,10,4,11,23,4,42,20,16,6,52,1,20,6,18,28,

%U 29,4,10,30,6,16,12,5,22,16,11,12,35,2,12,18,20,18,30,3,78,4,1,8,41,6,16,42

%N Period of repeating digits of 1/n in base 3.

%H T. D. Noe, <a href="/A007734/b007734.txt">Table of n, a(n) for n=1..1000</a>

%H <a href="/index/1#1overn">Index entries for sequences related to decimal expansion of 1/n</a>

%t f[n_] := MultiplicativeOrder[3, n/(3^IntegerExponent[n, 3])]; Array[f, 80] (* _Robert G. Wilson v_, Jun 10 2011 *)

%o (PARI) a(n)=znorder(Mod(3,n/3^valuation(n,3))) \\ _Charles R Greathouse IV_, Jun 10 2011

%K nonn,base

%O 1,4

%A _N. J. A. Sloane_, Hal Sampson (hals(AT)easynet.com)

%E More terms from _David W. Wilson_