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Number of pairs of orthogonal Latin squares of order n.
3

%I #22 Jan 16 2018 02:38:05

%S 1,0,36,3456,3110400,0,3131834388480000,32162058365970677760000,

%T 19083454070548282639185346560000

%N Number of pairs of orthogonal Latin squares of order n.

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

%H J. Egan and I. M. Wanless, <a href="http://dx.doi.org/10.1090/mcom/3010">Enumeration of MOLS of small order</a>, Mathematics of Computation 85, 2016, 799-824.

%H Ian Wanless, <a href="http://users.monash.edu.au/~iwanless/data/MOLS/">Data on MOLS</a>

%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/LatinSquare.html">Latin Square</a>

%Y Equals n!n!(n-1)!/2 times A266166 (except for the degenerate case n=1). Cf. A000315, A002860, A266167, A266168, A266169, A266170, A266171, A266172, A266173.

%K nonn,more

%O 1,3

%A _Eric W. Weisstein_, Jul 19 2002

%E More terms (and corrected the degenerate first term) from _Ian Wanless_, Dec 22 2015