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A075223 Number of polyiamonds with n cells that tile the plane isohedrally. 10
1, 1, 1, 3, 4, 12, 23, 66, 133, 316, 514, 1987, 2398, 6073, 12628, 29918, 26211, 108778, 95348, 375045, 498168, 780434, 843319, 4981628, 3691212, 7357764, 13169722, 33461765, 22372303, 117437124 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,4

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 Gr├╝nbaum 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, A075224, A075205, A075214.

Sequence in context: A243391 A000206 A240737 * A071332 A006791 A111358

Adjacent sequences:  A075220 A075221 A075222 * A075224 A075225 A075226

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

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Last modified November 13 12:45 EST 2019. Contains 329094 sequences. (Running on oeis4.)