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 A008980 #18 Feb 26 2020 13:38:13 %S A008980 2,3,10,39,204,1262,8984,67959,544504,4535030,39004772,344217402, %T A008980 3103896536 %N A008980 Number of immersions of the oriented circle into the oriented plane with n double points. %D A008980 V. I. Arnold, Topological Invariants of Plane Curves and Caustics, American Math. Soc., 1994, p. 16. %H A008980 S. M. Gusein-Zade and F. S. Duzhin, <a href="http://www.botik.ru/~duzhin/as/dataprog/">On the number of topological types of plane curves</a>; (Russian) Uspekhi Mat. Nauk 53 (1998), no. 3(321), 197-198. <a href="https://pdfs.semanticscholar.org/8e15/31bc512538a6e0dcd2f22d638d94c5682610.pdf">English translation</a>: Russian Mathematical Surveys 53 (1998) 626-627. %H A008980 S. M. Gusein-Zade and F. S. Duzhin, Enumeration of plane curves with up to 10 selfintersections, <a href="http://www.pdmi.ras.ru/~arnsem/dataprog/">Pascal program and result table</a>, 05 Apr 1998. %o A008980 (Pascal) Cf. link. %Y A008980 Cf. A008981, A008982, A008983, A008984, A008985, A054993. %K A008980 nonn,nice,more %O A008980 0,1 %A A008980 _N. J. A. Sloane_ %E A008980 Additional comments from _Sergei Duzhin_, Nov 11 2000 %E A008980 a(11)-a(12) from _Sean A. Irvine_, Apr 19 2018