A046904 Number of isomorphism classes of posets with n points with property that there is no nonsingelton proper subset T for which x not in T implies xT or x incomparable with every element of T.

1, 1, 0, 0, 1, 4, 28, 234

Offset: 0

Author

John A. Wright

Keywords

• nonn

References

• J. A. Wright, There are 718 6-point topologies, quasi-orderings and transgraphs, Notices Amer. Math. Soc., 17 (1970), p. 646, Abstract #70T-A106.

Links

• J. A. Wright, Letter to N. J. A. Sloane, Apr 06 1972, listing 18 sequences
• Index entries for sequences related to posets

Crossrefs

A subset of the posets enumerated in A003431. Cf. A046905.