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A209361
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Number of nX2 1..3 arrays with every element value z a city block distance of exactly z from another element value z
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1
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1, 2, 16, 122, 690, 4098, 24301, 131984, 720033, 3945050, 21470933, 115976303, 629975658, 3432416744, 18721854079, 102389248936, 560740694837, 3070272326544, 16802201754590, 91916873329401, 502611764211182
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OFFSET
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1,2
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COMMENTS
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LINKS
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EXAMPLE
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Some solutions for n=5
..2..3....1..3....2..3....3..3....1..2....1..3....2..2....2..3....3..2....3..3
..2..2....1..2....3..2....2..2....1..1....1..3....1..1....2..2....3..3....3..3
..3..2....2..2....3..2....3..2....3..2....3..3....2..2....3..2....2..2....3..3
..1..1....2..3....2..2....3..2....1..1....1..1....1..1....2..1....3..3....1..3
..1..2....2..2....3..2....2..2....1..3....3..3....1..2....1..1....2..2....1..3
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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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