A366340 Number of free (4,3)-polyominoids with n cells, allowing right-angled (or hard) connections only.

1, 1, 5, 19, 123, 954, 9324

Offset: 1

Author

Pontus von Brömssen, Oct 07 2023

Keywords

• nonn
• hard
• more

Comments

Two cubes sharing a face have a right-angled connection if they do not lie in the same 3-dimensional affine subspace.

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

Also, number of free polysticks in 4 dimensions with right-angled connections.

Links

• Wikipedia, Polyominoid.
• Index entries for sequences related to polyominoes.

Crossrefs

41st and 77th row of A366766.

Cf. A075679, A365654, A366336, A366338, A366341 (fixed).