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A075213
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Number of polyhexes with n cells that tile the plane isohedrally but not by translation or by 180-degree rotation (Conway criterion).
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10
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0, 0, 0, 0, 1, 1, 33, 88, 611, 1803, 2985, 21250, 23564, 100221, 392655, 438188, 433150, 4762862, 2327445, 18839643, 46717154
(list;
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refs;
listen;
history;
text;
internal format)
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OFFSET
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1,7
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COMMENTS
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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.
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REFERENCES
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Branko Grünbaum and G. C. Shephard, Tilings and Patterns. W. H. Freeman, New York, 1987, Section 9.4.
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LINKS
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CROSSREFS
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Cf. A070766, A075207, A075208, A075209, A075210, A075211, A075212, A075214, A075215, A075204, A075222.
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KEYWORD
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hard,nonn
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AUTHOR
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EXTENSIONS
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More terms from Herman Jamke (hermanjamke(AT)fastmail.fm), May 05 2007
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STATUS
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approved
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