%I A119679
%S A119679 2,3,22,4769,7,15853,114,9,28,35,14,1328467,68,111,1555,9569200211,76,
%T A119679 2030227,49,21,299,1097122717,51,546707,26,27,121,529,596,3095,138,93,
%U A119679 136,34723,45,589,198,87,18142961,595,292,319,318,117,55,20485243,91
%N A119679 a(n) = least k such that the remainder when 5^k is divided by k is n.
%C A119679 Comments from Alexander Adamchuk (alex(AT)kolmogorov.com), Jan 31 2007: 
               (Start)
%C A119679 a(n) > n.
%C A119679 Numbers n>1 such that a(n-1) = n are listed in A015951 = {1, 2, 3, 9, 
               21, 26, 27, 63, 81, ...} Numbers n such that n | 5^n + 1.
%H A119679 Robert G. Wilson v, <a href="a119679.txt">Table of n, a(n) for n = 1..10000 
               with -1 for those entries where a(n) has not yet been found</a>
%t A119679 Do[k = 1; While[PowerMod[5, k, k] != n, k++ ]; Print[k], {n, 30}]
%t A119679 Table[0, {10000}]; k = 1; lst = {}; While[k < 5000000000, a = PowerMod[5, 
               k, k]; If[ a < 10001 && t[[a]] == 0, t[[a]] = k; Print[{a,k}]]; k++ 
               ]; t
%Y A119679 Cf. A015951, A036236, A078457, A119678, A127816, A119715, A119714, A127817, 
               A127818, A127819, A127820, A127821.
%Y A119679 Sequence in context: A153256 A137077 A046965 this_sequence A130846 A114101 
               A114007
%Y A119679 Adjacent sequences: A119676 A119677 A119678 this_sequence A119680 A119681 
               A119682
%K A119679 nonn
%O A119679 1,1
%A A119679 Ryan Propper (rpropper(AT)stanford.edu), Jun 12 2006
%E A119679 a(58) <= 16860204577843069 from Joe K. Crump (joecr(AT)carolina.rr.com), 
               Feb 06 2007
%E A119679 Revised by Max Alekseyev (maxale(AT)gmail.com), Sep 25 2007
%E A119679 I changed the Mathematica coding to reflect the new limit. I also took 
               out all of the comment lines which are now in the b119679.txt text 
               file Robert G. Wilson v (rgwv(AT)rgwv.com), Jul 14 2009