The history of this problem will be found in _The Canterbury Puzzles_
(No. 90). Since the publication of that book in 1907, so far as I know,
nobody has succeeded in solving the case for that unlucky number of
persons, 13, seated at a table on 66 occasions. A solution is possible
for any number of persons, and I have recorded schedules for every
number up to 25 persons inclusive and for 33. But as I know a good many
mathematicians are still considering the case of 13, I will not at this
stage rob them of the pleasure of solving it by showing the answer. But
I will now display the solutions for all the cases up to 12 persons
inclusive. Some of these solutions are now published for the first time,
and they may afford useful clues to investigators.
The solution for the case of 3 persons seated on 1 occasion needs no
remark.