

A072377


Number of pairs of orthogonal Latin squares of order n.


3




OFFSET

1,3


COMMENTS

This sequence counts unordered pairs. The number of ordered pairs of MOLS is exactly double this sequence.


LINKS

Table of n, a(n) for n=1..9.
J. Egan and I. M. Wanless, Enumeration of MOLS of small order, Mathematics of Computation 85, 2016, 799824.
Ian Wanless, Data on MOLS
Eric Weisstein's World of Mathematics, Latin Square


CROSSREFS

Equals n!n!(n1)!/2 times A266166 (except for the degenerate case n=1). Cf. A000315, A002860, A266167, A266168, A266169, A266170, A266171, A266172, A266173.
Sequence in context: A303339 A034983 A291911 * A209267 A120349 A120359
Adjacent sequences: A072374 A072375 A072376 * A072378 A072379 A072380


KEYWORD

nonn,more


AUTHOR

Eric W. Weisstein, Jul 19 2002


EXTENSIONS

More terms (and corrected the degenerate first term) from Ian Wanless, Dec 22 2015


STATUS

approved



