login
This site is supported by donations to The OEIS Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A289269 Number of polygonal tiles with n sides with two exits per side and n edges connecting pairs of exits, with no edges between exits on the same side and non-isomorphic under rotational and reflectional, i.e. dihedral, symmetry. 3
0, 2, 4, 19, 80, 638, 6054, 76692, 1137284, 19405244, 370597430, 7825459362, 180862277352 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

The case n=2 is a degenerate polygon (two sides connecting two vertices). The two possibilities are when the edges cross and do not cross. Polygons start at n=3 with a triangle.

LINKS

Table of n, a(n) for n=1..13.

Marko Riedel, Hexagonal tiles

Marko Riedel, Maple code to compute number of tiles by ordinary enumeration and by Power Group Enumeration

Marko Riedel, Maple code for number of tiles using Burnside lemma.

CROSSREFS

See A053871 for tiles with no symmetries being taken into account, A289191 for tiles with rotational symmetries only being taken into account.

Sequence in context: A229485 A064228 A226891 * A272988 A168246 A212923

Adjacent sequences:  A289266 A289267 A289268 * A289270 A289271 A289272

KEYWORD

nonn,more

AUTHOR

Marko Riedel, Jun 29 2017

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 | More pages
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified August 17 17:04 EDT 2018. Contains 313816 sequences. (Running on oeis4.)