%I A127816
%S A127816 5,34,213,68,4021227877,7,121129,14,69,26,767,51,6191,22,201,20,1919,33,
%T A127816 169,44,39,1778,1926049,174,2673413,50,63,451,1257243481237,93,851,316,
%U A127816 183,14809,1969,38,1362959,1826,177,289,65,87,5567,1252,57,1651,6403249
%N A127816 a(n) = least k >= 1 such that the remainder when 6^k is divided by k 
               is n.
%C A127816 a(7^k-1) = 7^k.
%H A127816 Robert G. Wilson v, <a href="a127816.txt">Table of n, a(n) for n = 1..10000 
               with -1 for those entries where a(n) has not yet been found</a>
%F A127816 a(7^k-1) = 7^k.
%t A127816 t = Table[0, {10000}]; k = 1; lst = {}; While[k < 5600000000, a = PowerMod[6, 
               k, k]; If[ a<10001 && t[[a]]==0, t[[a]]=k; Print[{a,k}]]; k++ ]; 
               t
%Y A127816 Cf. A036236, A078457, A119678, A119679, A119715, A119714, A127817, A127818, 
               A127819, A127820, A127821.
%Y A127816 Sequence in context: A167023 A121831 A076708 this_sequence A024063 A015545 
               A102436
%Y A127816 Adjacent sequences: A127813 A127814 A127815 this_sequence A127817 A127818 
               A127819
%K A127816 hard,nonn
%O A127816 1,1
%A A127816 Alexander Adamchuk (alex(AT)kolmogorov.com), Jan 30 2007, Feb 05 2007
%E A127816 a(5) <= 20866130267 from Max Alekseyev (maxale(AT)gmail.com), Feb 06 
               2007
%E A127816 a(5) <= 4021227877 from Joe K. Crump (joecr(AT)carolina.rr.com), Feb 
               10 2007
%E A127816 a(29) <= 1257243481237 from Joe K. Crump (joecr(AT)carolina.rr.com), 
               Feb 09 2007
%E A127816 a(5) through a(28) from Ryan Propper (rpropper(AT)stanford.edu), Feb 
               21 2007
%E A127816 I combined the two Mathematica codings into one and extended the search 
               limits Robert G. Wilson v (rgwv(AT)rgwv.com), Jul 16 2009
%E A127816 a(29) as conjectured by J. K. Crump confirmed by Hagen von Eitzen (math(AT)von-eitzen.de), 
               Jul 21 2009
%E A127816 Corrected authorship of the a-file - R. J. Mathar (mathar(AT)strw.leidenuniv.nl), 
               Aug 24 2009