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 A067156 #17 Dec 04 2021 12:27:14 %S A067156 1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,35,0,0,0,0,0,123, %T A067156 0,0,88,45,0,0,0,0,0,51,0,0,0,165,0,114,0,118,120,61,124,0,192,195,66, %U A067156 67,272,138,0,568,360,146,222,600,0,231,156,237,800,567,410,664,84,255,344,174 %N A067156 Number of regions in regular n-gon which are 9-gons. %D A067156 B. Poonen and M. Rubinstein, Number of Intersection Points Made by the Diagonals of a Regular Polygon, SIAM J. Discrete Mathematics, Vol. 11, pp. 135-156. %H A067156 Scott R. Shannon, <a href="/A067156/b067156.txt">Table of n, a(n) for n = 9..765</a> %H A067156 Sascha Kurz, <a href="http://www.mathe2.uni-bayreuth.de/sascha/oeis/drawing/drawing.html">m-gons in regular n-gons</a> %H A067156 B. Poonen and M. Rubinstein, <a href="http://math.mit.edu/~poonen/">The number of intersection points made by the diagonals of a regular polygon</a>, SIAM J. on Discrete Mathematics, Vol. 11, No. 1, 135-156 (1998). %H A067156 <a href="/index/Pol#Poonen">Sequences formed by drawing all diagonals in regular polygon</a> %e A067156 a(9)=1 because drawing the regular 9-gon with all its diagonals yields 1 9-gon. %Y A067156 Cf. A007678, A067168, A064869, A067151, A067152, A067153, A067154, A067155, A067157, A067158, A067159. %K A067156 nonn %O A067156 9,27 %A A067156 _Sascha Kurz_, Jan 06 2002 %E A067156 a(86) and beyond by _Scott R. Shannon_, Dec 04 2021