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 A345649 #9 Jun 22 2021 12:26:20 %S A345649 0,5,61,465,1585,5257,9749,24025,38381,67177,100889,176005,210033, %T A345649 360877,450349,589581,779541,1127509,1251805,1806061,1970129,2504401, %U A345649 3116945,4017701,4163753,5433657,6335589 %N A345649 Number of vertices formed when connecting all 4n points on the perimeter of an n X n square by infinite lines. %C A345649 See A345459 for images of the polygons. %F A345649 a(n) = A345650(n) - A345459(n) + 1. %Y A345649 Cf. A345459 (number of polygons), A345650 (number of edges), A255011, A345648, A344993, A344857, A092098, A007678. %K A345649 nonn,more %O A345649 0,2 %A A345649 _Scott R. Shannon_ and _N. J. A. Sloane_, Jun 21 2021