From: "JA" <ymax@idirect.com>
Subject: Re: seeking the number of partial orders on a finite set
Date: Fri, 9 Jul 1999 14:11:57 -0400
Newsgroups: sci.math

You may find asymptotic evaluation of f(n) number of
different(non-isomorphic) p.o. sets of order n
in
Kleitman D.J. and Rotshild B.L. Trans. Amer. Math. Soc. 205(1975), 205-220

Juri.
==============================================================================

From: dontmailme@iname.com (Steamer)
Subject: Re: seeking the number of partial orders on a finite set
Date: Fri, 09 Jul 1999 19:17:33 GMT
Newsgroups: sci.math

Fred Nugen wrote:

>I'm working with partial orders, and I need to know how many strict
>partial orders there are on a finite set with n elements.

Sloane's sequences A000112 and A001035 (see
http://akpublic.research.att.com/~njas/sequences/SA.html)
give this information.  Which one you want depends on whether you want
to count them upto isomorphism or not.  There are lots of references on
enumeration of posets there as well (and also in the poset section of
http://akpublic.research.att.com/~njas/sequences/classic.html,
but these are probably the same references).

S.