A330847 The number of vertices inside a pentagon formed by the straight line segments mutually connecting all vertices and all points that divide the sides into n equal parts.

10, 121, 1055, 3506, 10410, 21111, 43740, 74526, 124490, 190291, 288190, 403321, 573805, 771191, 1027550, 1331896, 1721765, 2157301, 2712175, 3322441, 4067325, 4904491, 5900185, 6975151, 8268755, 9678566, 11297345, 13060231, 15102955, 17263311, 19784995

Offset: 1

Author

Scott R. Shannon and N. J. A. Sloane, Mar 07 2020

Keywords

• nonn

Comments

See the links in A331929 for images of the pentagons.

Links

• Lars Blomberg, Table of n, a(n) for n = 1..35

Crossrefs

Cf. A331929 (regions), A331939 (n-gons), A329710 (edges), A330846, A092866, A332599, A007569

Extensions

a(9) and beyond from Lars Blomberg, May 11 2020