%I A065819
%S A065819 7,209,10013,11687,12857,17537,27577,28067,700321,770431,1321189,
%T A065819 1542281,1681861,1963039,2282641,2313961,2664259,3308041,3709057,
%U A065819 3859207,3929761,4315751,4380541,4561381,5193001,5331001,5576519
%N A065819 4*EulerPhi[n] = 3*DivisorSigma[1,n].
%H A065819 Harry J. Smith, <a href="b065819.txt">Table of n, a(n) for n=1,...,65</
               a>
%e A065819 For m=10013, Phi[m]=8640,Sigma[m]=11520, 34560=4*Phi=3*Sigma.
%t A065819 Do[s = 4*EulerPhi[n]-3*DivisorSigma[1, n]; If[Equal[s, 0], Print[n]], 
               {n, 1, 10000000}]
%o A065819 (PARI) { n=0; for (m=1, 10^9, if (4*eulerphi(m) == 3*sigma(m), write("b065819.txt", 
               n++, " ", m); if (n==65, return)) ) } [From Harry J. Smith (hjsmithh(AT)sbcglobal.net), 
               Oct 31 2009]
%Y A065819 Cf. A000010, A000203, A062699
%Y A065819 Sequence in context: A124988 A128680 A157775 this_sequence A061028 A045760 
               A046033
%Y A065819 Adjacent sequences: A065816 A065817 A065818 this_sequence A065820 A065821 
               A065822
%K A065819 easy,nonn
%O A065819 1,1
%A A065819 Labos E. (labos(AT)ana.sote.hu), Nov 23 2001