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 A323276 #11 Jan 11 2019 19:22:54 %S A323276 0,4,68,964,12836,165784,2103788,26396416,328621604,4068021916, %T A323276 50142879128 %N A323276 Number of 4-regular maps on the Klein bottle with n vertices and 2n edges. %H A323276 Evgeniy Krasko, Alexander Omelchenko, <a href="https://doi.org/10.1016/j.disc.2018.07.013">Enumeration of r-regular maps on the torus. Part I: Rooted maps on the torus, the projective plane and the Klein bottle. Sensed maps on the torus</a>, Discrete Mathematics (2019) Vol. 342, Issue 2, 584-599. Also <a href="https://arxiv.org/abs/1709.03225">arXiv:1709.03225 [math.CO]</a>. See Th. 2.3 and Table 3. %K A323276 nonn,more %O A323276 0,2 %A A323276 _N. J. A. Sloane_, Jan 11 2019