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Number of isomorphism classes of 2-reductive abelian/medial quandles.
2

%I #15 Oct 01 2014 23:01:00

%S 1,1,2,5,15,55,246,1398,10301,98532,1246479,20837171,466087624,

%T 13943041873,563753074915,30784745506212

%N Number of isomorphism classes of 2-reductive abelian/medial quandles.

%C Both names "abelian" and "medial" refer to the identity (xy)(uv)=(xu)(yv). A quandle is called 2-reductive if all orbits are projection quandles.

%H P. Jedlička, A. Pilitowska, D. Stanovský, A. Zamojska-Dzienio, <a href="http://arxiv.org/abs/1409.8396">The structure of medial quandles</a>, arXiv:1409.8396 [math.GR], 2014.

%H David Stanovský, <a href="http://www.karlin.mff.cuni.cz/~stanovsk/quandles/">Calculating with quandles</a> GAP code to calculate the numbers.

%Y Cf. A165200.

%K nonn,hard

%O 1,3

%A _David Stanovsky_, Oct 01 2014