A066304 Reduced partially ordered sets (posets) with n unlabeled elements.

1, 1, 1, 3, 8, 30, 150

Offset

0,4

References

F. Bergeron, G. Labelle and P. Leroux, Combinatorial Species and Tree-Like Structures, Cambridge, 1998, p. 57 (1.4.70).

Links

Table of n, a(n) for n=0..6.

Index entries for sequences related to posets

Crossrefs

Cf. A000112. Euler transform of A066305.

Sequence in context: A261766 A078619 A274934 * A298456 A145776 A066165

Adjacent sequences: A066301 A066302 A066303 * A066305 A066306 A066307

Keyword

nonn,more

Author

Christian G. Bower, Dec 12 2001

Status

approved