login
This site is supported by donations to The OEIS Foundation.

 

Logo

Many excellent designs for a new banner were submitted. We will use the best of them in rotation.

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A076021 Number of fully idempotent systems with n elements having with one binary operation satisfying the equation B(AB)=A (semisymmetric quasigroups). 5
1, 0, 1, 1, 0, 0, 4, 0, 20 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,7

LINKS

Table of n, a(n) for n=1..9.

CROSSREFS

Cf. A076016-A076020.

Sequence in context: A058348 A184946 A085618 * A199933 A078630 A178671

Adjacent sequences:  A076018 A076019 A076020 * A076022 A076023 A076024

KEYWORD

nonn

AUTHOR

Richard Schroeppel , Oct 29 2002

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Transforms | Superseeker | Recent | More pages
The OEIS Community | Maintained by The OEIS Foundation Inc.

Content is available under The OEIS End-User License Agreement .

Last modified April 20 16:29 EDT 2014. Contains 240807 sequences.