|
| |
|
|
A006059
|
|
Number of connected labeled topologies with n points.
(Formerly M1948)
|
|
2
| |
|
|
1, 1, 2, 9, 76, 1095, 25386, 910161, 49038872, 3885510411, 445110425110, 72721717736613, 16755380125270788, 5393244363726095487, 2405910197342218830914, 1477264863856923105482745, 1241074736327051013648799024, 1419169006353332682835352361843
(list; graph; refs; listen; history; internal format)
|
|
|
|
OFFSET
| 0,3
|
|
|
REFERENCES
| M. Erne', Struktur- und Anzahlformeln fuer Topologien auf Endlichen Mengen, Manuscripta Math., 11 (1974), 221-259.
N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
|
|
|
LINKS
| Herman Jamke (hermanjamke(AT)fastmail.fm), Mar 02 2008, Table of n, a(n) for n = 0..19
|
|
|
FORMULA
| a(n)=n*A001035(n-1) for n>=1 - Herman Jamke (hermanjamke(AT)fastmail.fm), Mar 02 2008
|
|
|
CROSSREFS
| Sequence in context: A132621 A108992 A058164 * A182947 A006041 A192551
Adjacent sequences: A006056 A006057 A006058 * A006060 A006061 A006062
|
|
|
KEYWORD
| nonn,nice
|
|
|
AUTHOR
| N. J. A. Sloane (njas(AT)research.att.com).
|
|
|
EXTENSIONS
| More terms from Detlef Pauly (dettodet(AT)yahoo.de), Dec 27, 2001
|
| |
|
|
