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A228881
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Minimum number of spheres touching a wall of the container in the densest packing of n equal spheres into a cube.
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0
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1, 2, 3, 4, 5, 6, 7, 8, 8, 9, 10, 10, 13, 14, 14, 13, 16, 17, 12, 14, 8, 12, 20, 15, 19, 20, 26, 22, 25, 26, 27, 28, 22
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OFFSET
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1,2
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COMMENTS
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Spheres that are not part of the rigid framework, "rattlers", are always assumed not to touch the walls of the container cube.
If optimal configurations can be obtained by taking away an arbitrary sphere from a configuration with a higher sphere count, a sphere touching the container wall is chosen.
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LINKS
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EXAMPLE
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The first configuration in which there is an inner sphere not touching the walls occurs for n = 9, with 8 spheres in the corners of the cube and one sphere in the center of the cube. Therefore a(9) = 8.
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CROSSREFS
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KEYWORD
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nonn,more
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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