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 A008988 #47 Mar 29 2024 12:45:02 %S A008988 1,1,2,6,21,97,579,3812,27328,206410,1625916,13241177,110859326, %T A008988 950069179,8307012899,73908363060,667683905600 %N A008988 Number of immersions of oriented circle into unoriented sphere with n double points. %C A008988 a(10) = 1625916 by sampling method (to be confirmed, cf. ref. arXiv:1507.03163). - _Robert Coquereaux_, Nov 23 2015 %C A008988 a(10) = 1625916 confirmed. - _Brendan McKay_, Mar 29 2024 %D A008988 V. I. Arnold, Topological Invariants of Plane Curves and Caustics, American Math. Soc., 1994, p. 18. %D A008988 Guy Valette, A Classification of Spherical Curves Based on Gauss Diagrams, Arnold Math J. (2016) 2:383-405, DOI 10.1007/s40598-016-0049-3. %H A008988 R. Coquereaux and J.-B. Zuber, <a href="http://arxiv.org/abs/1507.03163">Maps, immersions and permutations</a>, arXiv preprint arXiv:1507.03163 [math.CO], 2015-2016. Also <a href="http://dx.doi.org/10.1142/S0218216516500474">DOI</a>, J. Knot Theory Ramifications 25, 1650047 (2016). %o A008988 (Magma) // see A260885 %Y A008988 Cf. A008986, A008987, A008989. First line of triangle A260885. %K A008988 nonn,nice,more %O A008988 0,3 %A A008988 _N. J. A. Sloane_ %E A008988 a(6)-a(7) from _Guy Valette_, Feb 09 2004 %E A008988 a(8)-a(9) from _Robert Coquereaux_ and Jean-Bernard Zuber, Jul 21 2015 %E A008988 a(10) from same source added by _N. J. A. Sloane_, Mar 03 2016 %E A008988 a(11)-a(16) from _Brendan McKay_, Mar 29 2024