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A219521
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Number of 4Xn arrays of the minimum value of corresponding elements and their horizontal, diagonal or antidiagonal neighbors in a random, but sorted with lexicographically nondecreasing rows and columns, 0..1 4Xn array
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1
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5, 9, 22, 68, 166, 380, 821, 1700, 3374, 6430, 11784, 20830, 35631, 59161, 95611, 150769, 232486, 351241, 520819, 759117, 1089094, 1539882, 2148076, 2959222, 4029523, 5427784, 7237618, 9559936, 12515745, 16249279, 20931489, 26763919
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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) = (1/40320)*n^8 - (1/3360)*n^7 + (7/576)*n^6 - (7/60)*n^5 + (1567/5760)*n^4 + (2201/160)*n^3 - (116111/672)*n^2 + (251961/280)*n - 1757 for n>9
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EXAMPLE
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Some solutions for n=3
..0..0..1....0..0..0....0..0..1....0..0..1....0..0..1....0..0..0....0..0..1
..0..0..1....0..0..0....0..0..0....0..0..1....1..0..1....0..0..0....0..0..1
..0..0..1....0..0..1....0..0..0....0..0..0....1..1..1....0..0..0....1..0..1
..1..0..1....1..0..0....0..1..0....0..0..0....1..1..1....1..1..1....1..1..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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