login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A333139 The number of regions inside a decagon formed by the straight line segments mutually connecting all vertices and all points that divide the sides into n equal parts. 5
220, 4220, 25220, 84280, 217800, 456640, 873090, 1501520, 2436020, 3736540, 5523970, 7830800, 10879460, 14665340, 19398660, 25173960, 32203320, 40502280, 50458120, 61995140, 75517160 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

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

LINKS

Table of n, a(n) for n=1..21.

Scott R. Shannon, Decagon regions for n = 1.

Scott R. Shannon, Decagon regions for n = 2.

Scott R. Shannon, Decagon regions for n = 3.

Scott R. Shannon, Decagon regions with random distance-based coloring for n = 1.

Scott R. Shannon, Decagon regions with random distance-based coloring for n = 2.

Scott R. Shannon, Decagon regions with random distance-based coloring for n = 3.

Wikipedia, Decagon.

CROSSREFS

Cf. A332417 (n-gons), A332418 (vertices), A332419 (edges), A007678, A092867, A331452, A331929.

Sequence in context: A258537 A027797 A055663 * A022042 A095702 A271674

Adjacent sequences:  A333136 A333137 A333138 * A333140 A333141 A333142

KEYWORD

nonn,more

AUTHOR

Scott R. Shannon and N. J. A. Sloane, Mar 09 2020

EXTENSIONS

a(6)-a(21) from Lars Blomberg, May 18 2020

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified October 17 21:17 EDT 2021. Contains 348065 sequences. (Running on oeis4.)