A231091 Number of distinct (modulo reflection and rotation) unicursal star polygons (not necessarily regular, no edge joins adjacent vertices) that can be formed by connecting the vertices of a regular n-gon.

0, 0, 0, 0, 1, 1, 5, 27, 175, 1533, 14361, 151575, 1735869, 21594863

Offset

1,7

Comments

For polygons in general see A000939 and A000949, and especially the Golomb-Welch reference. - N. J. A. Sloane, Nov 21 2013

Links

Table of n, a(n) for n=1..14.

Stewart Gordon, The five possible stars for n=7 (SVG file)

Wikipedia, Unicursal hexagram

Example

For n=5, only solution is the regular pentagram.
For n=6, only solution is the unicursal hexagram (see Wikipedia link).
For n=7, two regular heptagrams and three irregular forms are possible.

Crossrefs

Cf. A000939, A000940.

Sequence in context: A091101 A185622 A225309 * A205774 A326094 A232683

Adjacent sequences: A231088 A231089 A231090 * A231092 A231093 A231094

Keyword

nonn,nice

Author

Stewart Gordon, Nov 03 2013

Status

approved