%I #19 Jan 02 2017 02:00:42
%S 1,3,15,255,65535,4139059,15734689,66322477,83623935,4294967295
%N Odd numbers n such that 2^n == phi(n) (mod n).
%o (PARI) is(n)=Mod(2, n)^n==eulerphi(n)&&n%2==1;
%Y Cf. A000010, A000079, A015910.
%K nonn,more
%O 1,2
%A _Altug Alkan_, Dec 11 2016