Asymptotic enumeration of partial orders on a finite set

D. J. Kleitman, B. L. Rothschild
1975 Transactions of the American Mathematical Society  
By considering special cases, the number Pn of partially ordered sets on a set of n elements is shown to be (1 + 0(\¡n))Qn, where Qn is the number of partially ordered sets in one of the special classes. The number Qn can be estimated, and we ultimately obtain '»-('+0©)C5lC)(7)<"-^-^)-
doi:10.1090/s0002-9947-1975-0369090-9 fatcat:kthdzlv4qfgihg5eegvtlxlpwi