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A194993
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Number of lower triangles of an n X n 0..3 array with each element differing from all of its horizontal and vertical neighbors by one
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1
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4, 10, 42, 248, 2290, 31042, 641376, 19753266, 918924546, 64065187024, 6724991990090, 1059952700132050, 251257954485037072, 89488725743024413554, 47916300899545924260762, 38558096411377540692559456
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OFFSET
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1,1
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COMMENTS
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LINKS
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EXAMPLE
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Some solutions for 4X4
..1........3........2........3........1........2........1........3
..2.3......2.1......1.2......2.1......0.1......3.2......2.1......2.3
..1.2.3....1.2.3....2.1.2....3.2.3....1.2.3....2.1.2....1.2.1....3.2.1
..0.1.2.3..0.1.2.3..3.2.3.2..2.3.2.3..2.3.2.1..3.2.1.2..2.1.2.3..2.1.0.1
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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STATUS
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approved
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