A197553 Number of free poly-IH12-tiles (holes allowed) with n cells.

1, 2, 7, 24, 99, 416, 1852, 8386, 38797, 181530, 858560, 4092031, 19636098, 94750833

Offset: 1

Author

Joseph Myers, Oct 16 2011

Keywords

• hard
• nonn

Comments

Equivalently, polyhexes where two polyhexes are considered equivalent if and only if they are related by a translation or a reflection or glide reflection in a line in one fixed direction perpendicular to the sides of the hexagons.

References

• Branko Grünbaum and G. C. Shephard, Tilings and Patterns. W. H. Freeman, New York, 1987, Sections 6.2 and 9.4.

Crossrefs

Cf. A000228, A001207, A006535, A057973, A197549, A197550, A197551, A197552, A197554.