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 A301894 #9 Mar 28 2018 17:47:11 %S A301894 3,7,15,27 %N A301894 Number of real lines on a smooth real cubic surface. %C A301894 Schläfli proved that a smooth real cubic surface contains either 3, 7, 15, or 27 straight lines. %H A301894 D. Schläfli, <a href="http://rstl.royalsocietypublishing.org/content/153/193">On the distribution of surfaces of the third order into species, in reference to the absence or presence of singular points, and the reality of their lines</a>, Philosophical Transactions of the Royal Society of London, 153 (1863), 193-241. %H A301894 Kirsten Wickelgren, <a href="http://www.ams.org/journals/notices/201804/rnoti-p401.pdf">An Arithmetic Count of the Lines on a Smooth Cubic Surface</a>, AMS Notices, 65 (2018), 404-405. %F A301894 a(n) = A097080(n) = 2*n^2 - 2*n + 3 for n = 1, 2, 3, 4. %e A301894 The number of lines on a smooth complex cubic surface is a(4) = A027363(2) = A238370(1) = 27. %Y A301894 Cf. A027363, A238370. %K A301894 nonn,fini,full %O A301894 1,1 %A A301894 _Jonathan Sondow_, Mar 28 2018