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A075222
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Number of polyiamonds 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, 0, 0, 2, 10, 22, 54, 52, 534, 523, 1339, 3218, 9315, 2177, 29426, 15423, 101314, 140072, 110794, 46748, 1639279, 710736, 970251, 3002062, 8462256, 895291, 29458807
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,7
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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.
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REFERENCES
| Branko Gruenbaum and G. C. Shephard, Tilings and Patterns. W. H. Freeman, New York, 1987, Section 9.4.
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LINKS
| Joseph Myers, Polyiamond tiling
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CROSSREFS
| Cf. A071332, A075216, A075217, A075218, A075219, A075220, A075221, A075223, A075224, A075204, A075213.
Sequence in context: A032526 A096183 A079605 * A005962 A120548 A120845
Adjacent sequences: A075219 A075220 A075221 * A075223 A075224 A075225
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KEYWORD
| hard,nonn
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AUTHOR
| Joseph Myers (jsm(AT)polyomino.org.uk), Sep 08 2002
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EXTENSIONS
| More terms from Joseph Myers (jsm(AT)polyomino.org.uk), Nov 11 2003
a(29) and a(30) from Joseph Myers (jsm(AT)polyomino.org.uk), Nov 21 2010
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