A365650 Number of free n-polyominoids, allowing both corner- and edge-connections.

1, 4, 36, 660, 16687

Offset: 1

Author

Pontus von Brömssen, Sep 17 2023

Keywords

• nonn
• hard
• more

Comments

These structures could be called polypletoids (or pseudo-polyominoids), because they are related to polyplets (polyominoids) as polyominoids (pseudo-polyominoes) are related to polyominoes.

Links

• Pontus von Brömssen, Illustration for sizes 1..3.
• Index entries for sequences related to polyominoes.

Crossrefs

Cf. A000105 (polyominoes), A030222 (polyplets), A075679 (polyominoids), A365651 (fixed), A365652 (corner-connections only).

30th row of A366766.