Here I investigate the related question: how few cells can you remove from the plane to exclude the shape of a given polycairo? If you find a more efficient exclusion, please write.
To exclude either dicairo you must remove at least 1/2 the cells. This also holds for the two tricairos:
These tricairos are excluded optimally. The tetracairos are probably optimal.
This pattern optimally excludes six tetracairos:
This pattern optimally excludes three tetracairos:
These tetracairos are optimally excluded by these patterns:
These patterns are the best known for excluding these tetracairos:
Last revised 2018-05-28.