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 A292104 #28 Jun 08 2025 13:48:41 %S A292104 0,0,0,1,5,12,35,40,126,140,330,228,715,644,1365,1168,2380,1512,3876, %T A292104 3360,5985,5280,8855,6144,12650,11284,17550,15680,23751,13800,31465, %U A292104 28448,40920,37264,52360,42444,66045,60648,82251,75720,101270,75012,123410,114400,148995,138644,178365,152064 %N A292104 Number of interior points that are the intersections of exactly two chords in the configuration A006561(n). %H A292104 Seiichi Manyama, <a href="/A292104/b292104.txt">Table of n, a(n) for n = 1..10000</a> (terms 1..120 from Scott R. Shannon) %H A292104 N. J. A. Sloane, <a href="/A331450/a331450.jpg">Summary table for vertices and regions in regular n-gon with all chords drawn, for n = 3..19.</a> [V = total number of vertices (A007569), V_i (i>=2) = number of vertices where i lines cross (A292105, A292104, A101363); R = total number of cells or regions (A007678), R_i (i>=3) = number of regions with i edges (A331450, A062361, A067151).] %Y A292104 Cf. A006561. Column k=2 of A292105. %K A292104 nonn %O A292104 1,5 %A A292104 _N. J. A. Sloane_, Sep 14 2017 %E A292104 a(31)-a(48) from _Scott R. Shannon_, Mar 04 2022