The Conjecture has been numerically checked for a large range of
values of n.
It is an interesting problem to find efficient algorithms to test the
conjecture on a computer.
The current record for verifying the Conjecture seems to be held
by Nabuo Yoneda at the University of Tokyo,
who has reportedly checked it for all
[2].
In several places the statement appears that A. S. Fraenkel has checked that
all have a finite total stopping time;
this statement is erroneous [32].