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 A060679 Orders of non-cyclic groups. 7

%I

%S 4,6,8,9,10,12,14,16,18,20,21,22,24,25,26,27,28,30,32,34,36,38,39,40,

%T 42,44,45,46,48,49,50,52,54,55,56,57,58,60,62,63,64,66,68,70,72,74,75,

%U 76,78,80,81,82,84,86,88,90,92,93,94,96,98,99,100,102,104,105,106,108

%N Orders of non-cyclic groups.

%C Numbers n such that x^n==1 (mod n) has solutions 2<=x<=n - _Benoit Cloitre_, May 10 2002

%H Charles R Greathouse IV, <a href="/A060679/b060679.txt">Table of n, a(n) for n = 1..10000</a>

%F a(n) = n + O(n/log log log n). - _Charles R Greathouse IV_, Apr 16 2012

%o (PARI) is(n)=gcd(n,eulerphi(n))>1 \\ _Charles R Greathouse IV_, Apr 16 2012

%Y Complement of A003277.

%K nonn

%O 1,1

%A Ahmed Fares (ahmedfares(AT)my-deja.com), Apr 19 2001

%E More terms from _Vladeta Jovovic_, Jul 05 2001

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Last modified August 4 21:32 EDT 2021. Contains 346455 sequences. (Running on oeis4.)