|
|
A118641
|
|
Number of nonisomorphic finite non-associative, invertible loops of order n.
|
|
2
|
|
|
|
OFFSET
|
5,2
|
|
COMMENTS
|
These are non-associative loops in which every element has a unique inverse and it includes IP, Moufang and Bol loops [Cawagas]. The data were generated and checked by a supercomputer of 48 Pentium II 400 processors, specially built for automated reasoning, in about three days. In general, a loop is a quasigroup with an identity element e such that xe = x and ex = x for any x in the quasigroup. All groups are loops. A quasigroup is a groupoid G such that for all a and b in G, there exist unique c and d in G such that ac = b and da = b. Hence a quasigroup is not required to have an identity element, nor be associative. Equivalently, one can state that quasigroups are precisely groupoids whose multiplication tables are Latin squares (possibly empty).
|
|
REFERENCES
|
Cawagas, R. E., Terminal Report: Development of the Theory of Finite Pseudogroups (1998). Research supported by the National Research Council of the Philippines (1996-1998) under Project B-88 and B-95.
|
|
LINKS
|
|
|
EXAMPLE
|
a(5) = 1 (which is non-Abelian).
a(6) = 33 (7 Abelian + 26 non-Abelian).
a(7) = 2333 (16 Abelian + 2317 non-Abelian).
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn,bref,more
|
|
AUTHOR
|
|
|
STATUS
|
approved
|
|
|
|