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%I #22 Dec 31 2019 13:54:32
%S 10,15,16,18,20,24,26,28,30,32,34,35,36,40,42,44,45,48,50,51,52,54,56,
%T 57,58,60,63,64,65,66,68,70,72,74,75,76,77,78,80,81,82,84,85,88,90,91,
%U 92,96,98,99,100,102,104,105,106,108,110,111,112,114,116,117,119,120,122,124
%N Numbers k such that there exists a non-Cayley vertex-transitive graph of order k.
%C Numbers k for which A185959(k) < A006799(k).
%C Numbers k for which A006792(k) <> 0.
%C In the Farrokhi reference, a Cayley number is a number k such that all vertex transitive graphs of order k are Cayley graphs.
%H M. Farrokhi D. G., <a href="/A330698/a330698.txt">List of known non-Cayley numbers less than or equal to 1000000</a>
%H M. Farrokhi D. G., <a href="https://iasbs.ac.ir/~farrokhi/pages/miscellaneous/cayleynumbers.html">Cayley numbers</a>
%H M. Farrokhi D. G., <a href="https://github.com/mohammadfarrokhi/CayleyNumbers">Cayley numbers</a> (GitHub)
%Y Cf. A006792, A006799, A185959, A330697.
%K nonn
%O 1,1
%A _M. Farrokhi D. G._, Dec 26 2019