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

1,2

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.

Links

Table of n, a(n) for n=1..14.

Crossrefs

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

Sequence in context: A150434 A150435 A150436 * A213950 A123764 A150437

Adjacent sequences: A197550 A197551 A197552 * A197554 A197555 A197556

Keyword

hard,nonn

Author

Joseph Myers, Oct 16 2011

Status

approved