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A251038
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Number of (1+1)X(n+1) 0..3 arrays with nondecreasing min(x(i,j),x(i,j-1)) in the i direction and nondecreasing absolute value of x(i,j)-x(i-1,j) in the j direction
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1
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110, 711, 4050, 21720, 110852, 546600, 2624313, 12343573, 57116869, 260828863, 1178253507, 5274772080, 23435131926, 103447436545, 454103279511, 1983776981901, 8629751790534, 37401619581258, 161567196684667
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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) = 10*a(n-1) -25*a(n-2) -30*a(n-3) +146*a(n-4) +31*a(n-5) -287*a(n-6) -50*a(n-7) +239*a(n-8) +59*a(n-9) -86*a(n-10) -27*a(n-11) +11*a(n-12) +4*a(n-13)
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EXAMPLE
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Some solutions for n=4
..1..2..1..3..2....0..3..1..0..0....0..1..3..0..3....2..1..3..1..3
..1..2..1..3..2....0..2..2..1..3....0..1..3..1..1....2..2..2..2..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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