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A075211
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Number of polyhexes with n cells that tile the plane by 180-degree rotation (Conway criterion).
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10
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1, 1, 3, 7, 21, 75, 256, 929, 3090, 9235, 21216, 80463, 138623, 423595, 1160355, 2456117, 4272856, 15986299, 21709209, 75452662, 156068738
(list;
graph;
refs;
listen;
history;
text;
internal format)
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OFFSET
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1,3
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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, A075212, A075213, A075214, A075215, A075202, A075220.
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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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STATUS
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approved
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