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A219681
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Number of nX3 arrays of the minimum value of corresponding elements and their horizontal, vertical or antidiagonal neighbors in a random, but sorted with lexicographically nondecreasing rows and nonincreasing columns, 0..2 nX3 array
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1
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6, 8, 31, 99, 269, 655, 1506, 3356, 7278, 15335, 31362, 62286, 120292, 226281, 415250, 744464, 1305597, 2242405, 3775972, 6240154, 10130551, 16171179, 25404010, 39307716, 59953312, 90205963, 133984022, 196588422, 285117878, 408987989
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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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FORMULA
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Empirical: a(n) = (1/39916800)*n^11 - (1/3628800)*n^10 + (1/362880)*n^9 + (5/24192)*n^8 - (5639/1209600)*n^7 + (11267/172800)*n^6 - (26249/90720)*n^5 - (45251/36288)*n^4 + (5226461/226800)*n^3 - (303403/3150)*n^2 + (229729/1386)*n - 88 for n>4
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EXAMPLE
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Some solutions for n=3
..0..0..0....2..1..1....0..0..0....1..0..0....1..0..0....1..0..0....0..0..0
..0..0..0....2..1..1....0..0..0....1..0..0....0..0..0....1..0..0....0..0..0
..2..1..1....2..1..1....1..1..1....1..1..2....0..0..2....2..0..0....2..0..0
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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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