%N Members of 2-cycles of permutation A111273.
%C Trajectory of n under map k -> A111273(k) is periodic with period length 2.
%C n = A111273(A111273(n)) and n <> A111273(n).
%C Apparently A111273 has infinitely many 2-cycles.
%e A111273(122) = 183 and A111273(183) = 122, hence 122 and 183 are in the
%Y Cf. A111273, A113659, A113701.
%A _Klaus Brockhaus_, Nov 08 2005