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%I #6 Dec 08 2017 16:59:40
%S 2,4,6,8,9,10,12,14,16,18,20,21,22,24,26,27,28,30,32,33,34,36,38,39,
%T 40,42,44,45,46,48,49,50,52,54,55,56,57,58,60,62,63,64,66,68,70,72,74,
%U 75,76,77,78,80,82,84,86,88,90,91,92,93,94,95,96,98,99,100,102,104,105,106,108,110,111,112,114,115
%N Numbers n for which there is at least one x < n such that phi(x) = phi(n).
%C Numbers n for which A081373(n) > 1.
%C Apart from the initial term 2, this is the complement of union of A000040 (primes) and A069823.
%H Antti Karttunen, <a href="/A296214/b296214.txt">Table of n, a(n) for n = 1..12973</a>
%o (PARI) for(n=1,200,y=0;s=eulerphi(n);for(k=1,(n-1),if(eulerphi(k)==s,y=1;break)); if(y,print1(n,",")));
%Y Cf. A000010, A069822, A069823, A081373.
%Y Cf. A296087 (a subsequence).
%K nonn
%O 1,1
%A _Antti Karttunen_, Dec 08 2017
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