This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A386231 #9 Jul 21 2025 17:49:12 %S A386231 1,1,4,9,42,154,1064,6678,73780 %N A386231 Number of symmetric racks of order n, up to isomorphism. %C A386231 A good involution f of a rack R is an involution that commutes with all inner automorphisms and satisfies the identity f(y)(x) = y^-1(x). We call the pair (R,f) a symmetric rack. A symmetric rack isomorphism is a rack isomorphism that intertwines good involutions. %D A386231 Seiichi Kamada, Quandles with good involutions, their homologies and knot invariants, Intelligence of Low Dimensional Topology 2006, World Scientific Publishing Co. Pte. Ltd., 2007, 101-108. %H A386231 Lực Ta, <a href="https://arxiv.org/abs/2505.08090">Good involutions of conjugation subquandles</a>, arXiv:2505.08090 [math.GT], 2025. See Table 1. %H A386231 Lực Ta, <a href="https://github.com/luc-ta/Symmetric-Rack-Classification">Symmetric-Rack-Classification</a>, GitHub, 2025. %o A386231 (GAP) # See Ta, GitHub link %Y A386231 Cf. A386232, A181770, A383828, A386233, A386234. %Y A386231 Other sequences related to racks and quandles: A383144, A181771, A176077, A179010, A193024, A254434, A177886, A196111, A226173, A236146, A248908, A165200, A242044, A226193, A242275, A243931, A257351, A198147, A225744, A226172, A226174, A383828-A383831, A383145, A383146, A178432, A385041, A383145, A181769. %K A386231 nonn,hard,more %O A386231 0,3 %A A386231 _Luc Ta_, Jul 16 2025