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 A067498 #7 Apr 01 2022 11:39:31 %S A067498 1,3,7,11,21,27,43,51,69,83,111,123,157,171,199,227,273 %N A067498 Maximum number of reflections for a ray of light which reflects at n points (reflecting more than once at most or all points). %C A067498 The maxima occur when the points of reflection are arranged at the vertices of a regular n-gon and the ray (except entering and leaving) follows the edges and diagonals of the polygon. %H A067498 M. Oskar van Deventer, Point Mirror Reflection, in <a href="https://web.archive.org/web/20110807034947/http://g4g4.com/paul/BOOK.pdf">The Mathemagician and the Pied Puzzler</a> edited by E. Berlekamp and T. Rodgers, A K Peters Publishers, 1999, pp. 245-251. <a href="https://books.google.de/books?id=w8O2DwAAQBAJ">google books</a>. %F A067498 For p prime, a(p)=p^2-p+1. %F A067498 a(n) <= n^2-n+1. [Deventer eq (1)] %F A067498 a(n) <= n^2-2*n+3 for even n [Deventer eq. (2)] %Y A067498 Cf. A119959 (subsequence). %K A067498 more,nonn %O A067498 1,2 %A A067498 _Henry Bottomley_, Feb 22 2002