

A331929


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


12



11, 170, 1161, 3900, 10741, 22380, 44491, 76610, 126336, 194070, 290651, 410860, 577721, 779340, 1035676, 1345030, 1730696, 2176040, 2724036, 3345880, 4087656, 4933200, 5921991, 7018210, 8300896, 9723300, 11339151, 13122120, 15150271, 17345140, 19843056
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OFFSET

1,1


COMMENTS

The terms are from numeric computation  no formula for a(n) is currently known.


LINKS

Lars Blomberg, Table of n, a(n) for n = 1..35
Scott R. Shannon, Pentagon regions for n = 1.
Scott R. Shannon, Pentagon regions for n = 2.
Scott R. Shannon, Pentagon regions for n = 3.
Scott R. Shannon, Pentagon regions for n = 4.
Scott R. Shannon, Pentagon regions for n = 5.
Scott R. Shannon, Pentagon regions for n = 6.
Scott R. Shannon, Pentagon regions for n = 7.
Scott R. Shannon, Pentagon regions for n = 8.
Scott R. Shannon, Pentagon regions for n = 5, random distancebased coloring.
Scott R. Shannon, Pentagon regions for n = 6, random distancebased coloring
Wikipedia, Pentagon.


CROSSREFS

Cf. A331939 (ngons), A329710 (edges), A330847 (vertices), A007678, A092867, A331452, A331931.
Sequence in context: A157944 A233290 A167245 * A205087 A064182 A139792
Adjacent sequences: A331926 A331927 A331928 * A331930 A331931 A331932


KEYWORD

nonn


AUTHOR

Scott R. Shannon and N. J. A. Sloane, Feb 01 2020


EXTENSIONS

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


STATUS

approved



