A351924 The number of vertices on a diagonal of a regular 2n-gon when all its vertices are connected by lines and where the diagonal passes through the center of the 2n-gon.

3, 5, 7, 11, 15, 21, 27, 29, 43, 53, 59, 75, 87, 85, 115, 131, 135, 165, 183, 185, 223, 245, 251, 291, 315, 317, 367, 395, 379, 453, 483, 485, 547, 581, 587, 651, 687, 689, 763, 803, 795, 885, 927, 925, 1015, 1061, 1067, 1155, 1203, 1205, 1303, 1355, 1359, 1461, 1515, 1517, 1627, 1685, 1659

Offset: 2

Author

Scott R. Shannon, Feb 25 2022

Keywords

• nonn

Comments

No formula for a(n) is currently known.

Examples

			a(3) = 5 as a diagonal of a 6-gon, when all its vertices are connected by lines and where the diagonal passes through the center of the 6-gon, has five vertices on it - the two outer vertices, the central vertex, and two more vertices formed by intersections of the central diagonal with other diagonals. See the linked image of the 6-gon.
		

Links

• Scott R. Shannon, Image of the 6-gon.
• Scott R. Shannon, Image of the 10-gon.
• Scott R. Shannon, Image of the 18-gon.
• Scott R. Shannon, Image of the 30-gon.

Crossrefs

Cf. A007569, A006561, A146212.