%I #13 May 09 2022 08:37:41

%S 1,3,39,111,175,183,219,333,459,471,549,579,657,831,939,969,1191,1263,

%T 1371,1413,1443,1623,1737,1839,1983,2019,2199,2271,2379,2493,2631,

%U 2817,2847,2907,2991,3279,3459,3573,3603,3639,3711,3789,3963,4113,4131,4143

%N Numbers k such that phi(k*sigma(k)) = phi(k)^2.

%H Amiram Eldar, <a href="/A082954/b082954.txt">Table of n, a(n) for n = 1..10000</a>

%t Select[Range[5000],EulerPhi[#*DivisorSigma[1,#]]==EulerPhi[#]^2&] (* _Harvey P. Dale_, Jan 25 2013 *)

%Y Cf. A000010, A000203, A127473.

%K nonn

%O 1,2

%A _Benoit Cloitre_, May 26 2003