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

1,1

Comments

See the links in A331906 for images of the pentagrams.

Links

Table of n, a(n) for n=1..30.

Crossrefs

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

Sequence in context: A139670 A231282 A357140 * A263945 A335609 A241871

Adjacent sequences: A333114 A333115 A333116 * A333118 A333119 A333120

Keyword

nonn

Author

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

Extensions

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

Status

approved