A333117 The number of vertices inside a pentagram formed by the straight line segments mutually connecting all vertices and all points that divide the sides into n equal parts.

26, 866, 6771, 24221, 64306, 132701, 259761, 453016, 734131, 1134081, 1673056, 2384606, 3326391, 4478286, 5941196, 7710796, 9901136, 12407581, 15497721, 19088991, 23256266, 28021386, 33537586, 39846196, 47092241, 55136771, 64103776, 74213991, 85642556, 98039461

Offset: 1

Author

Scott R. Shannon and N. J. A. Sloane, Mar 08 2020

Keywords

• nonn

Comments

See the links in A331906 for images of the pentagrams.

Crossrefs

Cf. A331906 (regions), A331907 (n-gons), A333118 (edges), A092866, A332599, A007569.

Extensions

a(7)-a(30) from Lars Blomberg, May 06 2020