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

Author

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

Keywords

• nonn

Comments

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

Links

• 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.