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 A333075 #18 May 14 2020 15:50:51 %S A333075 80,1488,9312,31552,83432,174816,339816,584176,953416,1463936,2173976, %T A333075 3074784,4294080,5790816,7664880,9952944,12757088,16036096,20013696, %U A333075 24577760,29973528,36161472,43314312,51334672 %N A333075 The number of regions inside an octagon formed by the straight line segments mutually connecting all vertices and all points that divide the sides into n equal parts. %C A333075 The terms are from numeric computation - no formula for a(n) is currently known. %H A333075 Scott R. Shannon, <a href="/A333075/a333075.png">Octagon regions for n = 1</a>. %H A333075 Scott R. Shannon, <a href="/A333075/a333075_1.png">Octagon regions for n = 2</a>. %H A333075 Scott R. Shannon, <a href="/A333075/a333075_2.png">Octagon regions for n = 3</a>. %H A333075 Scott R. Shannon, <a href="/A333075/a333075_3.png">Octagon regions for n = 4</a>. %H A333075 Scott R. Shannon, <a href="/A333075/a333075_4.png">Octagon regions using random distance-based coloring for n = 2</a>. %H A333075 Scott R. Shannon, <a href="/A333075/a333075_5.png">Octagon regions using random distance-based coloring for n = 3</a>. %H A333075 Scott R. Shannon, <a href="/A333075/a333075_6.png">Octagon regions using random distance-based coloring for n = 4</a>. %H A333075 Wikipedia, <a href="https://en.wikipedia.org/wiki/Octagon">Octagon</a>. %Y A333075 Cf. A333076 (n-gons), A333109 (vertices), A333110 (edges), A007678, A092867, A331452, A331931. %K A333075 nonn,more %O A333075 1,1 %A A333075 _Scott R. Shannon_ and _N. J. A. Sloane_, Mar 07 2020 %E A333075 a(7)-a(24) from _Lars Blomberg_, May 14 2020