A340644 - OEIS

%I #17 Jan 17 2021 11:30:25

%S 3,19,120,442,1332,2863,5871,10171,17358,26518,40590,57757,81735,

%T 110209,148158,192184,248772,313105,393429,483283,593490,715528,

%U 861660,1022281,1211811,1418515,1659108,1919842,2220204,2543527,2912751,3308305,3755922,4233730,4770150,5340529,5977071

%N 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 The terms are from numeric computation - no formula for a(n) is currently known.

%H Scott R. Shannon, <a href="/A340644/a340644.png">Vertices for n = 2</a>.

%H Scott R. Shannon, <a href="/A340644/a340644_1.png">Vertices for n = 3</a>.

%H Scott R. Shannon, <a href="/A340644/a340644_2.png">Vertices for n = 4</a>.

%H Scott R. Shannon, <a href="/A340644/a340644_3.png">Vertices for n = 5</a>.

%H Scott R. Shannon, <a href="/A340644/a340644_8.png">Vertices for n = 6</a>.

%H Scott R. Shannon, <a href="/A340644/a340644_5.png">Vertices for n = 10</a>.

%H Scott R. Shannon, <a href="/A340644/a340644_7.png">Vertices for n = 11</a>.

%H Wikipedia, <a href="https://en.wikipedia.org/wiki/Reuleaux_triangle">Reuleaux triangle</a>.

%Y Cf. A340639 (regions), A340613 (edges), A340614 (n-gons), A007678, A092867.

%K nonn

%O 1,1

%A _Scott R. Shannon_ and _N. J. A. Sloane_, Jan 14 2021