A365652 Number of free n-polyominoids, allowing corner-connections only.

1, 2, 19, 293, 6590, 168753

Offset

1,2

Comments

Two squares are allowed to meet in an edge, but the structure must be connected through pure corner-connections (where the two squares meet in a single point) only. There are 3 such cases of size 3; see the linked illustration.

Links

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

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

Index entries for sequences related to polyominoes.

Crossrefs

Cf. A075679 (polyominoids, edge-connections only), A365650 (corner- and edge-connections), A365653 (fixed).

27th row of A366766.

Sequence in context: A252710 A065923 A293946 * A094476 A375860 A304637

Adjacent sequences: A365649 A365650 A365651 * A365653 A365654 A365655

Keyword

nonn,hard,more

Author

Pontus von Brömssen, Sep 17 2023

Status

approved