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

1, 4, 36, 660, 16687

Offset

1,2

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

Table of n, a(n) for n=1..5.

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.

Sequence in context: A002084 A135867 A268470 * A214347 A208732 A356616

Adjacent sequences: A365647 A365648 A365649 * A365651 A365652 A365653

Keyword

nonn,hard,more

Author

Pontus von Brömssen, Sep 17 2023

Status

approved