OFFSET
0,2
COMMENTS
This sequence counts free polyforms where holes are allowed. This means that two polyforms are considered the same if one is a rigid transformation (translation, rotation, reflection or glide reflection) of the other.
LINKS
EXAMPLE
See the PDF in the links section.
CROSSREFS
Analogous for other tilings: A000105 (square), A000228 (hexagonal), A000577 (triangular), A197156 (prismatic pentagonal), A197159 (floret pentagonal), A197459 (rhombille), A197462 (kisrhombille), A197465 (tetrakis square), A309159 (snub square), A343398 (trihexagonal), A343406 (truncated hexagonal), A343577 (truncated square).
KEYWORD
nonn,more
AUTHOR
Drake Thomas, Jun 07 2021
STATUS
approved