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A386556
Number of 2-colorings of an 6 X 6 X 6 grid / cube, up to rotational symmetry, by the number of black cells.
4
1, 11, 1013, 69045, 3677374, 155822419, 5479820520, 164392285865, 4294750355129, 99256405950180, 2054607644379763, 38477196919023712, 657318781413490584, 10314848558604181280, 149565304110190970723, 2014146095209708440612, 25302710321203873065217, 297678944953786351579885, 3291006113657215317985320
OFFSET
0,2
COMMENTS
This sequence is finite, having 6^3+1 terms. The cycle index Z(C) of the permutation group C of the rotations of the cube acting on the cells is given by 1/24 (a[1]^216 + 8 * a[1]^6 * a[3]^70 + 9 * a[2]^108 + 6 * a[4]^54).
REFERENCES
F. Harary and E. M. Palmer, Graphical Enumeration, Academic Press, 1973, page 35.
LINKS
FORMULA
a(n) = [z^n] Z(C; 1+z).
CROSSREFS
KEYWORD
nonn,fini,full
AUTHOR
Marko Riedel, Jul 25 2025
STATUS
approved