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 A340644 #17 Jan 17 2021 11:30:25 %S A340644 3,19,120,442,1332,2863,5871,10171,17358,26518,40590,57757,81735, %T A340644 110209,148158,192184,248772,313105,393429,483283,593490,715528, %U A340644 861660,1022281,1211811,1418515,1659108,1919842,2220204,2543527,2912751,3308305,3755922,4233730,4770150,5340529,5977071 %N A340644 The number of vertices on a Reuleaux triangle formed by the straight line segments mutually connecting all vertices and all points that divide the sides into n equal parts. %C A340644 The terms are from numeric computation - no formula for a(n) is currently known. %H A340644 Scott R. Shannon, <a href="/A340644/a340644.png">Vertices for n = 2</a>. %H A340644 Scott R. Shannon, <a href="/A340644/a340644_1.png">Vertices for n = 3</a>. %H A340644 Scott R. Shannon, <a href="/A340644/a340644_2.png">Vertices for n = 4</a>. %H A340644 Scott R. Shannon, <a href="/A340644/a340644_3.png">Vertices for n = 5</a>. %H A340644 Scott R. Shannon, <a href="/A340644/a340644_8.png">Vertices for n = 6</a>. %H A340644 Scott R. Shannon, <a href="/A340644/a340644_5.png">Vertices for n = 10</a>. %H A340644 Scott R. Shannon, <a href="/A340644/a340644_7.png">Vertices for n = 11</a>. %H A340644 Wikipedia, <a href="https://en.wikipedia.org/wiki/Reuleaux_triangle">Reuleaux triangle</a>. %Y A340644 Cf. A340639 (regions), A340613 (edges), A340614 (n-gons), A007678, A092867. %K A340644 nonn %O A340644 1,1 %A A340644 _Scott R. Shannon_ and _N. J. A. Sloane_, Jan 14 2021