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A066283
Number of 3-dimensional polyominoes (or polycubes) with n cells and rotational symmetry group of order exactly 6.
7
0, 0, 0, 0, 0, 1, 0, 0, 0, 2, 0, 5, 2, 4, 3, 8, 4, 28, 14, 20, 20, 41
OFFSET
1,10
COMMENTS
The sequence counts "one-sided" polycubes (A000162); chiral polycubes count twice. - John Mason, Sep 18 2024
REFERENCES
W. F. Lunnon, Symmetry of cubical and general polyominoes, pp. 101-108 of R. C. Read, editor, Graph Theory and Computing. Academic Press, NY, 1972.
FORMULA
a(n) = 2*CD(n)+CF(n), see Lunnon paper for naming convention. - John Mason, Sep 18 2024
KEYWORD
nonn,more,changed
AUTHOR
Brendan Owen (brendan_owen(AT)yahoo.com), Jan 01 2002
EXTENSIONS
Name clarified and more terms from John Mason, Sep 18 2024
STATUS
approved