A075212 Number of polyhexes with n cells that tile the plane by translation or by 180-degree rotation (Conway criterion).

1, 1, 3, 7, 21, 75, 257, 930, 3104, 9265, 21304, 81392, 139612, 427454, 1176912, 2491134, 4319362, 16243200, 21965930, 76738851, 158374741

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, A075211, A075213, A075214, A075215, A075203, A075221.

Sequence in context: A001576 A169587 A075211 * A319123 A173794 A049365

Adjacent sequences: A075209 A075210 A075211 * A075213 A075214 A075215

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