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A270862
Number of polycubes with n cells, allowing edge connections as well as face connections, distinguishing mirror images.
2
1, 2, 9, 88, 1103, 17570, 295506, 5168034, 92436673
OFFSET
1,2
REFERENCES
Jørgen Lou, Danish Patent 126840 (27 August 1973).
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
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