|
| |
|
|
A046912
|
|
Number of irreducible quasiorders with n labeled points.
|
|
1
| |
|
|
1, 1, 2, 11, 147, 3412, 121553, 6353629, 476850636, 50811255045, 7636459252135, 1610584897516674, 474333338553730879, 194055026319667963777, 109692570582311591696890, 85221064877720762475072503
(list; graph; refs; listen; history; internal format)
|
|
|
|
OFFSET
| 0,3
|
|
|
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.
|
|
|
FORMULA
| E.g.f.: A(x) = 2-1/B(x), where B(x) is e.g.f. of A000798. - Vladeta Jovovic (vladeta(AT)eunet.rs), Jan 10 2006
|
|
|
CROSSREFS
| Cf. A046911.
Sequence in context: A193209 A204243 A203203 * A185245 A006122 A111014
Adjacent sequences: A046909 A046910 A046911 * A046913 A046914 A046915
|
|
|
KEYWORD
| nonn
|
|
|
AUTHOR
| John A. Wright.
|
|
|
EXTENSIONS
| Corrected and extended by Vladeta Jovovic (vladeta(AT)eunet.rs), Jan 10 2006
|
| |
|
|
