New Results from an Algorithm for Counting Posets.
Joseph C. Culberson and Gregory J. E. Rawlins
Order vol 7:361-374, 1991.
Abstract
In this paper we report on the success of a new technique for computing the
number of unlabeled partial orders on n elements based on the partial
order of partial orders ordered by containment. In addition to the number of
partial orders, we obtain complete enumerations of the number of partial orders
on n elements with r relations for n <= 11 ,
where r takes on all possible values. We point out some interesting
sequences that arise in these tables.
joe@cs.ualberta.ca