%I #7 Dec 14 2016 08:36:06

%S 5,7,8,9,11,13,15,16,17,19,20,21,23,24,25,27,28,29,31,32,33,35,36,37,

%T 39,40,41,43,44,45,47,48,49,51,52,53,55,56,57,59,60,61,63,64,65,67,68,

%U 69,71,72,73,75,76,77,79,80,81,83,84,85,87,88,89,91,92,93,95,96,97,99,100

%N Numbers n such that in Z/nZ the number of squares is strictly less than the number of invertible elements.

%H Ivan Neretin, <a href="/A122904/b122904.txt">Table of n, a(n) for n = 1..10000</a>

%F n such that A000224(n) < A000010(n)

%t Select[Range@100, Length@Union@Mod[Range[#]^2, #] < EulerPhi[#] &] (* _Ivan Neretin_, Dec 14 2016 *)

%Y Cf. A122903, A122905, A122906, A122907.

%K nonn

%O 1,1

%A _Max Alekseyev_, Sep 18 2006