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 A338660 #20 Dec 30 2021 00:24:07 %S A338660 1,2,5,13,43,167 %N A338660 Number of circle graphs of Gauss diagrams of meander curves with 2n+1 crossings. %C A338660 See A343358 for a definition of a graph corresponding to a closed planar curve. Meanders have been defined in various ways; for the purpose of considering their Gauss diagrams and graphs, a meander is understood as a closed planar curve in whose graph there is a vertex adjacent to every other vertex. This sequence is the number of distinct graphs of meanders of (necessarily odd) sizes. %D A338660 Delecroix, Vincent, et al. "Enumeration of meanders and Masur-Veech volumes." Forum of Mathematics, Pi. Vol. 8. Cambridge University Press, 2020. %D A338660 Grinblat, Andrey, and Viktor Lopatkin. "On realizabilty of Gauss diagrams and constructions of meanders." Journal of Knot Theory and Its Ramifications 29.05 (2020): 2050031. %H A338660 V. Delecroix et al. <a href="https://arxiv.org/abs/1705.05190">Enumeration of meanders and Masur-Veech volumes</a>, arXiv preprint arXiv:1705.05190 [math.GT], 2017-2019. %H A338660 Andrey Grinblat and Viktor Lopatkin. <a href="https://arxiv.org/abs/1808.08542">On realizabilty of Gauss diagrams and constructions of meanders.</a> arXiv:1808.08542 [math.AT], 2018. %H A338660 Abdullah Khan, Alexei Lisitsa, Viktor Lopatkin, and Alexei Vernitski, <a href="https://arxiv.org/abs/2108.02873">Circle graphs (chord interlacement graphs) of Gauss diagrams: Descriptions of realizable Gauss diagrams, algorithms, enumeration</a>, arXiv:2108.02873 [math.GT], 2021. %Y A338660 Cf. A343358. %K A338660 nonn,hard,more %O A338660 1,2 %A A338660 _Alexei Vernitski_, Apr 22 2021