OFFSET
1,3
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, Polyomino tiling
Eric Weisstein's World of Mathematics, Isohedral Tiling
CROSSREFS
KEYWORD
hard,nonn
AUTHOR
Joseph Myers, Sep 08 2002
EXTENSIONS
More terms from Joseph Myers, Nov 04 2003
a(24) and a(25) from Joseph Myers, Nov 17 2010
STATUS
approved