

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 x<T or x>T or x incomparable with every element of T.


1




OFFSET

0,6


REFERENCES

J. A. Wright, There are 718 6point topologies, quasiorderings and transgraphs, Notices Amer. Math. Soc., 17 (1970), p. 646, Abstract #70TA106.


LINKS

Table of n, a(n) for n=0..7.
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.
Sequence in context: A229646 A229645 A202824 * A030444 A093877 A151830
Adjacent sequences: A046901 A046902 A046903 * A046905 A046906 A046907


KEYWORD

nonn


AUTHOR

John A. Wright.


STATUS

approved



