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!)
A075210 Number of polyhexes with n cells that tile the plane by 180-degree rotation (Conway criterion) but not by translation. 10
0, 0, 0, 1, 9, 39, 197, 721, 2717, 8211, 19836, 74497, 132611, 403534, 1127416, 2364402, 4173316, 15604400, 21318428, 73965916, 154211880 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,5

REFERENCES

Branko Gr├╝nbaum and G. C. Shephard, Tilings and Patterns. W. H. Freeman, New York, 1987, Section 9.4.

LINKS

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

Joseph Myers, Polyhex tiling

CROSSREFS

Cf. A070766, A075207, A075208, A075209, A075211, A075212, A075213, A075214, A075215, A075201, A075219.

Sequence in context: A264085 A126396 A246065 * A146187 A173764 A331343

Adjacent sequences:  A075207 A075208 A075209 * A075211 A075212 A075213

KEYWORD

hard,nonn

AUTHOR

Joseph Myers, Sep 08 2002

EXTENSIONS

More terms from Joseph Myers, Nov 08 2003

More terms from Herman Jamke (hermanjamke(AT)fastmail.fm), May 05 2007

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 February 16 16:00 EST 2020. Contains 331961 sequences. (Running on oeis4.)