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 A363979 #26 Sep 09 2023 11:27:37 %S A363979 1,1,3,3,7,7,14,13,25,19,37,35,58,53,82,58,112,98,150,133,177,151,239, %T A363979 212,300,275,369,244,455,409,530,488,631,526,736,683,858,800,975,794, %U A363979 1133,1056,1291,1227,1487,1289,1666,1600,1889,1797,2102,1884,2373,2242,2621,2496,2878,2458 %N A363979 Number of nonsimilar polygonal regions in a regular n-gon with all diagonals drawn. %C A363979 Alternatively, the number of equivalence classes of an equivalence relation on the polygonal regions in a regular n-gon with all diagonals drawn, where two regions are equivalent iff they are similar. %H A363979 Bjorn Poonen and Michael Rubinstein, <a href="http://math.mit.edu/~poonen/papers/ngon.pdf">The Number of Intersection Points Made by the Diagonals of a Regular Polygon</a>, SIAM J. Discrete Mathematics 11 (1998), nr. 1, pp. 135-156; doi: <a href="http://dx.doi.org/10.1137/S0895480195281246">10.1137/S0895480195281246</a>; <a href="https://arxiv.org/abs/math/9508209">arXiv version</a>, arXiv:math/9508209 [math.MG], 1995-2006. %H A363979 Christopher Scussel, <a href="/A363979/a363979_1.pdf">Illustration of similarity without congruence at a(10)</a> %e A363979 This sequence is the same as A187781 for n<10 because n=10 is the smallest n such that there exist regions that are similar but not congruent. %Y A363979 Cf. A187781, A007678. %K A363979 nonn %O A363979 3,3 %A A363979 _Christopher Scussel_, Jun 30 2023