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A076016 Number of systems with n elements having with one binary operation satisfying the equation B(AB)=A (semisymmetric quasigroups). 5
1, 2, 3, 18, 120, 2880, 140256, 20782080, 9569532672 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Or, Latin squares with each row and column a permutation and corresponding rows and columns are inverse permutations.

LINKS

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

CROSSREFS

Cf. A076017-A076021.

Sequence in context: A166510 A288492 A184719 * A226961 A107095 A102939

Adjacent sequences:  A076013 A076014 A076015 * A076017 A076018 A076019

KEYWORD

nonn,hard,more

AUTHOR

Richard C. Schroeppel, Oct 29 2002

STATUS

approved

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Last modified October 26 05:15 EDT 2020. Contains 338027 sequences. (Running on oeis4.)