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 A335769 #13 Mar 24 2022 16:32:48 %S A335769 1,8,25,104,321,80,617,624,745,1056,1617,896,2233,2224,2465,3024,3929, %T A335769 2472,4809,4848,5193,5944,7217,5528,8305,8456,8929,9856,11513,9336, %U A335769 12849,13080,13617,14816,16809,13744,18417,18632,19329,20728,23073,19936,25001 %N A335769 a(n) is the number of regions formed by n-secting the angles of an octagon. %H A335769 Lars Blomberg, <a href="/A335769/b335769.txt">Table of n, a(n) for n = 1..200</a> %H A335769 Lars Blomberg, <a href="/A335769/a335769.png">Illustration for n=3</a> %H A335769 Lars Blomberg, <a href="/A335769/a335769_1.png">Illustration for n=4</a> %H A335769 Lars Blomberg, <a href="/A335769/a335769_2.png">Illustration for n=19</a> %H A335769 Lars Blomberg, <a href="/A335769/a335769_3.png">Illustration for n=20</a> %Y A335769 Cf. A333075 (n-sected sides, not angles), A335770 (vertices), A335771 (edges), A335772 (ngons). %K A335769 nonn %O A335769 1,2 %A A335769 _Lars Blomberg_, Jun 23 2020