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%I #19 Feb 14 2014 00:33:51
%S 1,1,1,2,4,1,1,2,3,4,10,2,12,1,4,2,16,3,3,4,1,10,22,2,4,12,9,2,7,4,15,
%T 4,10,16,4,6,9,3,12,4,40,1,6,10,12,22,23,2,1,4,16,12,26,9,20,2,3,7,29,
%U 4,60,15,3,8,12,10,66,16,22,4,70,6,24,9,4,6,10,12,78,4,27,40,41,2,16,6,7,10
%N Period of repeating digits of 1/n in base 7.
%H T. D. Noe, <a href="/A007738/b007738.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[7, n/(7^IntegerExponent[n, 7])]; Array[f, 80] (* _Robert G. Wilson v_, Jun 10 2011 *)
%o (PARI) a(n)=znorder(Mod(7,n/7^valuation(n,7))) \\ _Charles R Greathouse IV_, Jun 10 2011
%K nonn,base
%O 1,4
%A _N. J. A. Sloane_, Hal Sampson (hals(AT)easynet.com)
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