A075213 Number of polyhexes with n cells that tile the plane isohedrally but not by translation or by 180-degree rotation (Conway criterion).

0, 0, 0, 0, 1, 1, 33, 88, 611, 1803, 2985, 21250, 23564, 100221, 392655, 438188, 433150, 4762862, 2327445, 18839643, 46717154

Offset: 1

Author

Joseph Myers, Sep 08 2002

Keywords

• hard
• nonn

Comments

A tiling is isohedral if the symmetries of the tiling act transitively on the tiles; a shape is anisohedral if it tiles the plane, but not isohedrally.

References

• Branko Grünbaum and G. C. Shephard, Tilings and Patterns. W. H. Freeman, New York, 1987, Section 9.4.

Links

• Joseph Myers, Polyhex tiling

Crossrefs

Cf. A070766, A075207, A075208, A075209, A075210, A075211, A075212, A075214, A075215, A075204, A075222.

Extensions

More terms from Joseph Myers, Nov 08 2003

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