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A145242
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1/4 of the number of 4-colorings of an n X n array symmetric under 180 degree rotation.
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0
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1, 3, 51, 813, 75351, 6514173, 3287790591, 1547899100553, 4259466117807411, 10935733441872804453, 164161963716080866194651
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