A070287 - OEIS

%I #6 Mar 30 2012 18:38:58

%S 1,3,4,12,14,24,28,36,48,60,72,78,84,96,120,144,168,180,192,240,248,

%T 264,288,312,336,360,420,432,480,496,576,620,672,684,720,780,792,798,

%U 840,864,924,936,960,1008,1056,1080,1092,1104,1176,1240,1260,1344,1368

%N Numbers n such that the equation lcm(sigma(x),phi(x))=n has solutions.

%o (PARI) for(n=1,2000,if(0<sum(i=1,n,if(lcm(sigma(i),eulerphi(i))-n,0,1)),print1(n,",")))

%K easy,nonn

%O 1,2

%A _Benoit Cloitre_, May 10 2002