A366003 Number of free polyominoids with n cells, allowing right-angled corner-connections and right-angled edge-connections.

1, 2, 24, 359, 7882, 194076

Offset: 1

Author

Pontus von Brömssen, Sep 28 2023

Keywords

• nonn
• hard
• more

Comments

See A365995 for further details and a table of related sequences.

Links

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

Crossrefs

Cf. A365995, A366004 (fixed).

25th row of A366766.

Extensions

a(6) from Pontus von Brömssen, Mar 04 2025