%N Start with n, apply the map k -> A169639(k) until trajectory converges; sequence give full list of the 20 possible limit points.
%C There is a slight ambiguity in the definition, but I believe these are all the numbers which eventually return to themselves under iteration of k -> A169639(k). - _N. J. A. Sloane_, Jun 11 2021
%A _Jacques ALARDET_, Apr 04 2010
%E Edited by _N. J. A. Sloane_, Apr 05 2010