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

Author

Joseph Myers, Sep 08 2002

Keywords

• hard
• nonn

References

• Branko Grünbaum and G. C. Shephard, Tilings and Patterns. W. H. Freeman, New York, 1987, Section 9.4.

Links

• Joseph Myers, Polyhex tiling

Crossrefs

Cf. A070766, A075207, A075208, A075209, A075210, A075212, A075213, A075214, A075215, A075202, A075220.

Extensions

More terms from Joseph Myers, Nov 08 2003

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