%I #5 Mar 30 2012 17:37:43
%S 114190259,6364631939,10296994891,10429820759
%N Primes p of the form 4k+3 where sigma(phi(sigma(p)))= phi(sigma(phi(p))).
%C Between the first 480000000 primes, the equation (*): sigma(phi(sigma(x)))=phi(sigma(phi(x))) has 256 solutions q(i) and only four of them namely q(76),q(215),q(254) and q(256) are of the form 4k+3. Sequence A112017 gives composite solutions of the equation (*), which are of the form 4k+3.
%t Do[If[Mod[Prime[m], 4]==3 && DivisorSigma[1, EulerPhi[Prime[m]+1 ==EulerPhi[DivisorSigma[1, Prime[m]-1]], Print[Prime[m]]], {m, 480000000}]
%Y Cf. A112017.
%K more,nonn
%O 1,1
%A _Farideh Firoozbakht_, Sep 15 2005