%I A067384
%S A067384 121679,1043909,2350171,2918263,3396103,3566807,3688067,4019467,
%T A067384 4562827,5963407,7300697,7485979,7853933,8103301,8364151,9237779,
%U A067384 9514213,9638527,10531123,11094619,11384447,12721937,13576267
%N A067384 Numbers n such that sigma(phi(n))/sigma(n) = 4.
%C A067384 Subset of A066881. [From R. J. Mathar (mathar(AT)strw.leidenuniv.nl), 
               Sep 30 2008]
%t A067384 For[ n=1, True, n++, If[ DivisorSigma[ 1, EulerPhi[ n ] ]/DivisorSigma[ 
               1, n ]==4, Print[ n ] ] ]
%Y A067384 Cf. A033631, A066831, A067382, A067383, A067385.
%Y A067384 Sequence in context: A061128 A068136 A135495 this_sequence A066881 A048903 
               A115545
%Y A067384 Adjacent sequences: A067381 A067382 A067383 this_sequence A067385 A067386 
               A067387
%K A067384 nonn
%O A067384 1,1
%A A067384 Dean Hickerson (dean.hickerson(AT)yahoo.com), Jan 20 2002