%I A127821
%S A127821 2,11,5,51,44,7,15,371285,10,74853,158,13757837,17,5805311,22,2181,38,
%T A127821 25,30,9667,74,87,146,23441,88,19629779,35,45,70,235433,46,55,34,309,
%U A127821 134
%N A127821 a(n) = least k such that the remainder when 13^k is divided by k is n.
%H A127821 Robert G. Wilson v, <a href="a127821.txt">Table of n, a(n) for n = 1..10000 
               with -1 for large entries where a(n) has not yet been found</a>
%t A127821 t = Table[0, {10000} ]; k = 1; While[ k < 3500000000, a = PowerMod[13, 
               k, k]; If[a < 1001 && t[[a]] == 0, t[[a]] = k; Print[{a, k}]]; k++ 
               ]; t
%Y A127821 Cf. A036236, A078457, A119678, A119679, A127816, A119715, A119714, A127817, 
               A127818, A127819, A127820.
%Y A127821 Sequence in context: A087552 A124688 A158616 this_sequence A114724 A165768 
               A009258
%Y A127821 Adjacent sequences: A127818 A127819 A127820 this_sequence A127822 A127823 
               A127824
%K A127821 nonn
%O A127821 1,1
%A A127821 Alexander Adamchuk (alex(AT)kolmogorov.com), Jan 30 2007
%E A127821 More terms from Robert G. Wilson v (rgwv(at)rgwv.com), Feb 06 2007
%E A127821 a(54) <= 47941814519 from Joe K. Crump (joecr(AT)carolina.rr.com), Feb 
               09 2007