A075211 Number of polyhexes with n cells that tile the plane by 180-degree rotation (Conway criterion).

1, 1, 3, 7, 21, 75, 256, 929, 3090, 9235, 21216, 80463, 138623, 423595, 1160355, 2456117, 4272856, 15986299, 21709209, 75452662, 156068738

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, A075209, A075210, A075212, A075213, A075214, A075215, A075202, A075220.

Sequence in context: A148680 A001576 A169587 * A075212 A319123 A173794

Adjacent sequences: A075208 A075209 A075210 * A075212 A075213 A075214

Keyword

hard,nonn

Author

Joseph Myers, Sep 08 2002

Extensions

More terms from Joseph Myers, Nov 08 2003

a(20) and a(21) from Joseph Myers, Nov 21 2010

Status

approved