A075224 Number of anisohedral polyiamonds with n cells.

0, 0, 0, 0, 0, 0, 0, 0, 6, 25, 53, 47, 97, 281, 280, 343, 345, 1367, 619, 2478, 1504, 8292, 1811, 16742, 3458, 48453, 5459, 95311, 9416, 333739

Offset

1,9

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

Table of n, a(n) for n=1..30.

Joseph Myers, Polyiamond tiling

Crossrefs

Cf. A071332, A075216, A075217, A075218, A075219, A075220, A075221, A075222, A075223, A075206, A075215.

Sequence in context: A067926 A165217 A320422 * A364928 A042185 A065069

Adjacent sequences: A075221 A075222 A075223 * A075225 A075226 A075227

Keyword

hard,nonn

Author

Joseph Myers, Sep 08 2002

Extensions

More terms from Joseph Myers, Nov 11 2003

a(29) and a(30) from Joseph Myers, Nov 21 2010

Status

approved