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A253494
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Number of (n+1) X (7+1) 0..2 arrays with every 2 X 2 subblock diagonal minus antidiagonal sum nondecreasing horizontally, vertically and ne-to-sw antidiagonally.
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1
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48293, 51167, 60586, 82676, 127898, 220988, 415106, 827156, 1722698, 3728108, 8381906, 19618436, 47878298, 121758428, 321599906, 877526516, 2458110698, 7025471948, 20378773106, 59741111396, 176432995898, 523718388668
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OFFSET
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1,1
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LINKS
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FORMULA
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Empirical: a(n) = 6*a(n-1) - 11*a(n-2) + 6*a(n-3) for n>6.
Empirical: a(n) = 49*3^(n-1) + 5322*2^(n-1) + 38777 for n>3.
Empirical g.f.: x*(48293 - 238591*x + 284807*x^2 - 7761*x^3 - 8714*x^4 - 480*x^5) / ((1 - x)*(1 - 2*x)*(1 - 3*x)). - Colin Barker, Dec 16 2018
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EXAMPLE
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Some solutions for n=4:
..0..1..2..1..0..1..1..1....0..2..1..2..2..1..2..1....0..0..0..1..1..0..0..0
..1..1..2..1..0..1..1..1....0..2..1..2..2..1..2..1....2..1..1..2..2..1..1..1
..1..1..2..1..0..1..1..1....0..2..1..2..2..1..2..1....2..1..1..2..2..1..1..1
..1..1..2..1..0..1..1..1....0..2..1..2..2..1..2..1....1..0..0..1..1..0..0..0
..1..1..2..1..0..1..1..1....0..2..1..2..2..1..2..2....1..0..0..1..1..0..1..2
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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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