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 A335553 #11 Jun 20 2020 14:13:43 %S A335553 1,10,11,60,131,90,276,310,326,510,706,580,981,1070,1086,1390,1721, %T A335553 1320,2136,2250,2311,2730,3176,2900,3746,3900,3956,4530,5086,4690, %U A335553 5821,5980,6061,6760,7451,6720,8286,8540,8621,9420,10266,9700,11241,11510,11616,12560 %N A335553 a(n) is the number of regions formed by n-secting the angles of a pentagon. %H A335553 Lars Blomberg, <a href="/A335553/b335553.txt">Table of n, a(n) for n = 1..200</a> %H A335553 Lars Blomberg, <a href="/A335553/a335553.png">Illustration for n=3</a> %H A335553 Lars Blomberg, <a href="/A335553/a335553_1.png">Illustration for n=4</a> %H A335553 Lars Blomberg, <a href="/A335553/a335553_2.png">Illustration for n=17</a> %H A335553 Lars Blomberg, <a href="/A335553/a335553_3.png">Illustration for n=18</a> %Y A335553 Cf. A331929 (n-sected sides, not angles), A335554 (vertices), A335555 (edges), A335556 (ngons). %K A335553 nonn %O A335553 1,2 %A A335553 _Lars Blomberg_, Jun 14 2020