A075209 Number of polyhexes with n cells that tile the plane both by translation and by 180-degree rotation (Conway criterion).

1, 1, 3, 6, 12, 36, 59, 208, 373, 1024, 1380, 5966, 6012, 20061, 32939, 91715, 99540, 381899, 390781, 1486746, 1856858

Offset

1,3

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..21.

Joseph Myers, Polyhex tiling

Crossrefs

Cf. A070766, A075207, A075208, A075210, A075211, A075212, A075213, A075214, A075215, A075200, A075218.

Sequence in context: A033648 A102972 A392643 * A075207 A208131 A136121

Adjacent sequences: A075206 A075207 A075208 * A075210 A075211 A075212

Keyword

hard,nonn

Author

Joseph Myers, Sep 08 2002

Extensions

More terms from Joseph Myers, Nov 08 2003

More terms from Herman Jamke (hermanjamke(AT)fastmail.fm), May 05 2007

Status

approved