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 A345650 #9 Jun 22 2021 12:26:31 %S A345650 0,8,140,1032,3608,11308,21892,51000,83404,143900,217728,367132, %T A345650 456008,749328,952236,1251056,1649708,2327232,2653900,3717444,4158448, %U A345650 5243680,6488208,8241988,8780976,11235028,13116156 %N A345650 Number of polygon edges formed when connecting all 4n points on the perimeter of an n X n square by infinite lines. %C A345650 See A345459 for images of the polygons. %F A345650 a(n) = A345459(n) + A345649(n) - 1. %Y A345650 Cf. A331448 (number inside the square), A345459 (number of polygons), A345649 (number of vertices), A255011, A345648, A344993, A344857, A092098, A007678. %K A345650 nonn,more %O A345650 0,2 %A A345650 _Scott R. Shannon_ and _N. J. A. Sloane_, Jun 21 2021