%I #24 Jun 15 2022 04:09:09
%S 1,1,2,6,19,74,353,2080,16023,159526,2093244,36265070,836395102,
%T 25794670618
%N Number of isomorphism classes of racks of order n.
%H Přemysl Jedlička, Agata Pilitowska, Anna Zamojska-Dzienio, <a href="https://arxiv.org/abs/1901.01471">Multipermutation set theoretic solutions of the Yang-Baxter equation of level 2</a>, arXiv:1901.01471 [math.QA], 2019.
%H Sam Nelson, <a href="http://www1.cmc.edu/pages/faculty/VNelson/quandles.html">Quandles and Racks</a>
%H Petr Vojtěchovský and Seung Yeop Yang, <a href="https://doi.org/10.1090/mcom/3409">Enumeration of racks and quandles up to isomorphism</a>, Mathematics of Computation, 88 (2019), 2523-2540; arXiv:<a href="https://arxiv.org/abs/1911.04991">1911.04991</a> [math.QA], 2019.
%Y Cf. A181769.
%K nonn,hard,more
%O 0,3
%A _James McCarron_
%E a(9)-a(13) from Petr Vojtěchovský and Seung Yeop Yang added by _Andrey Zabolotskiy_, Jun 15 2022