A340686 The number of vertices on a concave circular triangle formed by the straight line segments mutually connecting all vertices and all points that divide the sides into n equal parts.

3, 10, 24, 76, 168, 391, 819, 1447, 2949, 4153, 6393, 8293, 12048, 14857, 20670, 25972, 33123, 41026, 50379, 63700, 76560, 96628, 113262, 135076, 160050, 183484, 215355, 244435, 288861, 322276, 371742, 424279, 470838, 534376, 597033, 682264, 760959, 854755, 941706, 1039255, 1141569, 1254190

Offset

1,1

Comments

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

Links

Table of n, a(n) for n=1..42.

Scott R. Shannon, Vertices for n = 2.

Scott R. Shannon, Vertices for n = 3.

Scott R. Shannon, Vertices for n = 4.

Scott R. Shannon, Vertices for n = 6.

Scott R. Shannon, Vertices for n = 8.

Scott R. Shannon, Vertices for n = 10.

Scott R. Shannon, Vertices for n = 14.

Scott R. Shannon, Vertices for n = 15.

Wikipedia, Circular triangle.

Crossrefs

Cf. A340685 (regions), A340687 (edges), A340688 (n-gons), A340644, A007678, A092867.

Sequence in context: A286209 A293797 A179608 * A192912 A168062 A176952

Adjacent sequences: A340683 A340684 A340685 * A340687 A340688 A340689

Keyword

nonn

Author

Scott R. Shannon and N. J. A. Sloane, Jan 16 2021

Status

approved