A270862 Number of polycubes with n cells, allowing edge connections as well as face connections, distinguishing mirror images.

1, 2, 9, 88, 1103, 17570, 295506, 5168034, 92436673

Offset

1,2

References

Jørgen Lou, Danish Patent 126840 (27 August 1973).

Links

Table of n, a(n) for n=1..9.

G. L. Sicherman, Catalogue of Polykedges.

Example

a(3)=9 because there are 8 ways to join 3 cells in the cubic grid at faces or edges, identifying reflections, and one of those 8 has distinct mirror images, which makes 9.

Crossrefs

Cf. A268666 (identifying mirror images), A000162, A030222 (2-dimensional polyplets).

Sequence in context: A360433 A278332 A135747 * A259794 A347013 A132431

Adjacent sequences: A270859 A270860 A270861 * A270863 A270864 A270865

Keyword

nonn,nice,more,hard

Author

George Sicherman, Mar 24 2016

Extensions

Terms a(8) and a(9) from Joerg Arndt and Márk Péter Légrádi, May 20 2023

Status

approved