A366007 Number of free polyominoids with n cells, allowing any corner-connections and flat edge-connections.

1, 3, 25, 431, 10175, 278475

Offset

1,2

Comments

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

Links

Table of n, a(n) for n=1..6.

Pontus von Brömssen, Illustration for sizes 1..3.

Wikipedia, Polyominoid.

Index entries for sequences related to polyominoes.

Crossrefs

Cf. A365995, A366008 (fixed).

28th row of A366766.

Sequence in context: A380197 A160143 A009843 * A182962 A223076 A336804

Adjacent sequences: A366004 A366005 A366006 * A366008 A366009 A366010

Keyword

nonn,hard,more

Author

Pontus von Brömssen, Sep 28 2023

Extensions

a(6) from Pontus von Brömssen, Oct 20 2025

Status

approved