A366338 Number of free (4,2)-polyominoids with n cells, allowing right-angled (or hard) connections only.

1, 1, 8, 44, 509, 7091

Offset

1,3

Comments

Two squares sharing an edge have a right-angled connection if they do not lie in the same plane.

Connections that are not right-angled (flat connections) may occur, but the polyominoids considered here must be connected through right-angled connections only.

Links

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

Wikipedia, Polyominoid.

Index entries for sequences related to polyominoes.

Crossrefs

45th row of A366766.

Cf. A075679, A365654, A366334, A366339 (fixed), A366340.

Sequence in context: A264819 A350128 A028565 * A129553 A174643 A181268

Adjacent sequences: A366335 A366336 A366337 * A366339 A366340 A366341

Keyword

nonn,hard,more

Author

Pontus von Brömssen, Oct 07 2023

Status

approved