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A220036
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Number of 6 X n arrays of the minimum value of corresponding elements and their horizontal or diagonal neighbors in a random, but sorted with lexicographically nondecreasing rows and nonincreasing columns, 0..1 6 X n array.
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1
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7, 12, 28, 83, 187, 358, 613, 962, 1426, 2034, 2823, 3839, 5137, 6782, 8850, 11429, 14620, 18538, 23313, 29091, 36035, 44326, 54164, 65769, 79382, 95266, 113707, 135015, 159525, 187598, 219622, 256013, 297216, 343706, 395989, 454603, 520119
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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) = (1/120)*n^5 - (1/12)*n^4 + (47/24)*n^3 - (23/12)*n^2 + (1771/30)*n - 323 for n>8.
G.f.: x*(7 - 30*x + 61*x^2 - 45*x^3 - 26*x^4 + 59*x^5 - 35*x^6 + 3*x^7 + 24*x^8 - 21*x^9 + 3*x^10 + x^11 - x^12 + x^13) / (1 - x)^6.
a(n) = 6*a(n-1) - 15*a(n-2) + 20*a(n-3) - 15*a(n-4) + 6*a(n-5) - a(n-6) for n>14.
(End)
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EXAMPLE
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Some solutions for n=3:
..1..0..0....0..0..0....0..0..0....0..0..0....1..0..0....0..0..0....0..0..0
..1..0..0....0..0..0....0..0..0....1..0..0....1..1..1....1..0..0....0..0..0
..1..0..0....1..0..0....0..0..0....1..1..1....1..1..1....1..0..0....0..0..0
..1..0..0....1..0..0....1..1..0....1..1..1....1..1..1....1..1..1....1..0..0
..1..0..0....1..1..1....1..1..1....1..1..1....1..1..1....1..1..1....1..0..0
..1..1..1....1..1..1....1..1..1....1..1..1....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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