login
The OEIS is supported by
the many generous donors to the OEIS Foundation
.
Hints
(Greetings from
The On-Line Encyclopedia of Integer Sequences
!)
A058122
Number of self-converse idempotent semigroups of order n.
2
1, 1, 1, 2, 6, 19, 68, 285
(
list
;
graph
;
refs
;
listen
;
history
;
text
;
internal format
)
OFFSET
0,4
LINKS
Table of n, a(n) for n=0..7.
Index entries for sequences related to semigroups
CROSSREFS
Main diagonal of
A058118
.
Sequence in context:
A150103
A150104
A145868
*
A150105
A150106
A150107
Adjacent sequences:
A058119
A058120
A058121
*
A058123
A058124
A058125
KEYWORD
nonn
,
hard
AUTHOR
Christian G. Bower
, Nov 10 2000
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 March 28 16:34 EDT 2024. Contains 371254 sequences. (Running on oeis4.)