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 A160860 #32 Dec 08 2017 17:43:54 %S A160860 1,4,11,24,47,80 %N A160860 The least possible number of pieces resulting from cutting a convex n-gon along all its diagonals. %C A160860 It seems that a(9)=137 and a(n) = A007678(n) for all even n. %H A160860 Vladimir Letsko, <a href="http://www-old.fizmat.vspu.ru/doku.php?id=marathon:illustrations_102_co">Illustration of all cases for number of sides from 3 to 8</a> %H A160860 Vladimir Letsko, <a href="/A160860/a160860.pdf">Illustration of all cases for number of sides from 3 to 8</a> [Cached copy, pdf version only] %H A160860 Vladimir Letsko, <a href="http://www-old.fizmat.vspu.ru/doku.php?id=marathon:problem_102">Proof for n = 7 and n = 8 and example for n = 9</a> (in Russian) %H A160860 Vladimir Letsko, <a href="/A160860/a160860_1.pdf">Proof for n = 7 and n = 8 and example for n = 9</a> (in Russian). [Cached copy, pdf version only] %H A160860 V. A. Letsko, M. A. Voronina, <a href="http://grani.vspu.ru/files/publics/1301378772.pdf">Classification of convex polygons</a>, Grani Poznaniya, 1(11), 2011. (in Russian) %H A160860 B. Poonen and M. Rubinstein, <a href="http://arXiv.org/abs/math.MG/9508209">The number of intersection points made by the diagonals of a regular polygon</a>. %Y A160860 Cf. A006522, A007678, A230281. %K A160860 hard,more,nonn,nice %O A160860 3,2 %A A160860 _Vladimir Letsko_, May 29 2009, May 30 2009, Apr 20 2010