%I
%S 1,7,49,343,889,2359,2401,6223,16513,16807,43561,112903,115591,117649,
%T 299593,304927,790321,794983,809137,823543,2033143,2097151,2134489,
%U 5532247,5564881,5663959,5764801,13549249,14232001,14338681,14680057,14941423,34591207,38048311,38725729
%N Numbers n such that n divides 8^n  1.
%C For all k, 7^k is in the sequence.  _Benoit Cloitre_, Mar 05 2002
%C From _Alexander Adamchuk_, May 16 2010: (Start)
%C 7 divides a(n) for n>1.
%C Prime divisors of a (n) in the order of their first appearance are {7, 127, 337, 2287, 15241, 14407, 18199, 42463, ...}. (End)
%H M. F. Hasler, <a href="/A014949/b014949.txt">Table of n, a(n) for n = 1..64</a>
%o (PARI) is(n)=Mod(8,n)^n==1 \\ _Charles R Greathouse IV_, Nov 04 2016
%K nonn
%O 1,2
%A _Olivier GĂ©rard_
%E More terms from _Benoit Cloitre_, Mar 05 2002
%E a(15)a(31) from _Alexander Adamchuk_, May 16 2010
%E More terms from _M. F. Hasler_, Nov 21 2018
