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 A330913 #13 May 03 2020 06:05:27 %S A330913 4,8,16,34,63,113,185,253,438,638,854,1228,1641,1825,2783,3543,4304, %T A330913 5508,6748,7745,9859,11773,13653,16409,19178,21838,25770,29648,32696, %U A330913 38683,43899,48903,55916,62784,69604,78378,87175,95699,106993,118093,128431,142838 %N A330913 The number of vertices formed by straight line segments mutually connecting all vertices of a semicircular polygon defined in A333642. %C A330913 See A333642 for a precise definition of the polygon and images. %H A330913 Lars Blomberg, <a href="/A330913/b330913.txt">Table of n, a(n) for n = 1..100</a> %Y A330913 Cf. A333642 (regions), A330911 (edges), A330914 (n-gons), A331453, A333026, A006561. %K A330913 nonn %O A330913 1,1 %A A330913 _Scott R. Shannon_ and _N. J. A. Sloane_, May 02 2020 %E A330913 a(21) and beyond from _Lars Blomberg_, May 03 2020