%I
%S 1209,27474741,55385589,222850677
%N Numbers n such that sigma(phi(n))=2n.
%C No other terms below 10^10.
%e sigma(phi(222850677))=sigma(118879488)=445701354=2*222850677, so 222850677 is in the sequence.
%t Do[If[DivisorSigma[1,EulerPhi[n]]==2n,Print[n]],{n,420000000}]
%Y Cf. A135240.
%K more,nonn
%O 1,1
%A _Farideh Firoozbakht_, Dec 26 2007
%E Search extended to 10^10 by _Max Alekseyev_, Sep 25 2009
