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A046909 Number of isomorphism classes of connected irreducible quasiorders with n labeled points. 1
1, 1, 1, 1, 2, 17, 167, 1672 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,5

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

Table of n, a(n) for n=0..7.

J. A. Wright, Letter to N. J. A. Sloane, Apr 06 1972, listing 18 sequences

CROSSREFS

Cf. A046910.

Sequence in context: A231616 A003419 A126109 * A041879 A011550 A102023

Adjacent sequences:  A046906 A046907 A046908 * A046910 A046911 A046912

KEYWORD

nonn

AUTHOR

John A. Wright.

STATUS

approved

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Last modified September 23 02:41 EDT 2021. Contains 347609 sequences. (Running on oeis4.)