login
A076020
Number of systems with n elements with one binary operation satisfying the equation B(AB)=A (semisymmetric quasigroups). This gives numbers of systems which are isomorphic to their transpose but are noncommutative.
1
0, 0, 0, 1, 3, 6, 24, 178, 1328
OFFSET
1,5
CROSSREFS
KEYWORD
nonn,hard,more
AUTHOR
Richard C. Schroeppel, Oct 29 2002
STATUS
approved