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 A385040 #13 Jul 09 2025 17:34:38 %S A385040 1,1,4,15,71,350,2372,18543,199491 %N A385040 Number of isomorphism classes of virtual racks of order n. %C A385040 A virtual rack is a rack equipped with a distinguished rack automorphism. Two virtual racks (R1,f1), (R2,f2) are isomorphic if there exists a rack isomorphism g: R1 -> R2 such that g*f1 = f2*g. %H A385040 Alessia Cattabriga and Timur Nasybullov, <a href="https://doi.org/10.1007/s13398-017-0445-0">Virtual quandle for links in lens spaces</a>, RACSAM, 112 (2008), no. 3, 657-669. %H A385040 Vassily Olegovich Manturov, <a href="https://doi.org/10.1023/A:1016258728022">On invariants of virtual links</a>, Acta Applicandae Mathematicae, 72 (2002), no. 3, 295-309. %H A385040 Lực Ta, <a href="https://github.com/luc-ta/Virtual-Rack-Classification">Virtual-Rack Classification</a>, GitHub, 2025. %H A385040 Lực Ta, <a href="https://arxiv.org/abs/2506.16536">Enumeration of virtual quandles up to isomorphism</a>, arXiv:2506.16536 [math.GT], 2025. See p. 5. %o A385040 (GAP) See Ta, GitHub link %Y A385040 Cf. A385041, A383145, A181769, A181770. %Y A385040 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 %K A385040 nonn,hard,more %O A385040 0,3 %A A385040 _Luc Ta_, Jun 16 2025 %E A385040 a(4)-a(8) corrected by _Luc Ta_, Jul 05 2025