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%I #6 Dec 05 2016 02:41:07
%S 1,3,12,107,951,10923
%N Number of (-1,0,1) periodic irreducible matrices up to sign change, transposition and mirroring over the antidiagonal.
%C "Irreducible" is intended to mean "not factoring into blocks along the diagonal". The periods for n=6 are 396 times period 3, 2939 times period 4, 1684 times period 6 and 5904 times period 12.
%H Wouter Meeussen, <a href="http://users.pandora.be/Wouter.Meeussen/PseudoAntiSymmetricMatrixPowers.nb">Periodic</a>
%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/PeriodicMatrix.html">Periodic Matrices</a>
%Y Cf. A072148.
%K hard,nonn
%O 1,2
%A _Wouter Meeussen_, Nov 15 2005