A191101 Number of regions in a complete but borderless regular polygon.

6, 18, 43, 72, 145, 210, 364, 432, 768, 938, 1441, 1680, 2483, 2448, 4010, 4480, 6154, 6798, 9063, 9000, 12901, 13962, 17848, 19152, 24100, 21450, 31869, 33824, 41383, 43758, 52886, 52920, 66638, 69958, 82915, 86760, 102009

Offset

5,1

Comments

A complete borderless polygon is one where each vertex is connected to every other vertex except for adjacent vertices. Adjacent vertices are not connected by edges. The result is a polygon interior.

Links

Table of n, a(n) for n=5..41.

Formula

a(n) = A007678(n) - n.

Crossrefs

Cf. A007678.

Sequence in context: A334839 A272250 A272700 * A184630 A009957 A344992

Adjacent sequences: A191098 A191099 A191100 * A191102 A191103 A191104

Keyword

nonn,easy

Author

Stefan Hannie, May 25 2011

Extensions

a(8) onward corrected by T. D. Noe, Jun 02 2011

Status

approved