%I
%S 1,2,3,4,5,6,7,8,9,11,12,16,17,22,23,27,28,33,34,38,39,40,44,45,49,50,
%T 51,55,56,61,62,66,67,72,73,77,78,83,84,88,89,90,94,95,99,111,112,116,
%U 117,222,223,227,228,333,334,338,339,440,444,445,449
%N Numbers n such that for some k>0, n*k=1 in the arithmetic defined in A169918.
%C These would be the units if the structure formed a ring (which it does not).
%e 22 is a member since 22*88 = 1. So is 23 since 23*8 = 1. 10 is not a member, even though 10 divides 9, since 10*9 = 0.
%K nonn,base
%O 1,2
%A _David Applegate_, _Marc LeBrun_ and _N. J. A. Sloane_, Jul 21 2010
