login
The OEIS is supported by
the many generous donors to the OEIS Foundation
.
Hints
(Greetings from
The On-Line Encyclopedia of Integer Sequences
!)
A018195
Possible numbers of complements of topologies on 4 points.
0
1, 3, 4, 7, 12, 14, 15, 16
(
list
;
graph
;
refs
;
listen
;
history
;
text
;
internal format
)
OFFSET
0,2
LINKS
Table of n, a(n) for n=0..7.
J. I. Brown and S. Watson,
The number of complements of a topology on n points is at least 2^n (except for some special cases)
, Discr. Math., 154 (1996), 27-39.
CROSSREFS
Sequence in context:
A244819
A305185
A083561
*
A086417
A051215
A192112
Adjacent sequences:
A018192
A018193
A018194
*
A018196
A018197
A018198
KEYWORD
nonn
,
more
AUTHOR
N. J. A. Sloane
.
STATUS
approved
Lookup
|
Welcome
|
Wiki
|
Register
|
Music
|
Plot 2
|
Demos
|
Index
|
Browse
|
More
|
WebCam
Contribute new seq. or comment
|
Format
|
Style Sheet
|
Transforms
|
Superseeker
|
Recents
The OEIS Community
| Maintained by
The OEIS Foundation Inc.
License Agreements, Terms of Use, Privacy Policy.
.
Last modified April 26 03:05 EDT 2024. Contains 371989 sequences. (Running on oeis4.)