%I #19 Jun 30 2024 04:17:39

%S 1,1,2,5,16,62,303,1842,14073,134802

%N Number of connected chainmails with n unlabeled elements.

%C In a poset, a mail is a nonempty set of elements of the poset having a common lower bound. A chainmail is a poset in which every mail has a join. A chainmail is connected if it's connected as a poset.

%H J. F. Du Plessis, Z. Janelidze, and B. A. Wessels, <a href="https://arxiv.org/abs/2406.16923">A Primer on Chainmails: Structures for Point-free Connectivity</a>, arXiv:2406.16923 [math.GM], 2024.

%K nonn,hard,more

%O 1,3

%A _Jean F. du Plessis_, Jun 27 2024