login
Number of quasi-orders with n elements.
(Formerly M2755)
4

%I M2755 #18 Nov 08 2017 15:55:14

%S 1,1,3,8,26,94,435,2564,19983,205729

%N Number of quasi-orders with n elements.

%D N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

%H M. Erné and K. Stege, <a href="/A006870/a006870.pdf">The number of partially ordered (labeled) sets</a>, Preprint, 1989. (Annotated scanned copy)

%H M. Erné and K. Stege, <a href="http://dx.doi.org/10.1007/BF00383446">Counting Finite Posets and Topologies</a>, Order, 8 (1991), 247-265.

%K nonn,nice,more

%O 0,3

%A _N. J. A. Sloane_