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A250903
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Number of (5+1) X (n+1) 0..2 arrays with nondecreasing 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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4213, 15111, 44525, 119359, 305429, 764315, 1893433, 4673299, 11537593, 28584535, 71295237, 179606071, 458428429, 1188689987, 3137057025, 8433329995, 23088675409, 64300637535, 181823356333, 520893887439, 1508445493253
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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) = 14*a(n-1) - 85*a(n-2) + 294*a(n-3) - 639*a(n-4) + 906*a(n-5) - 839*a(n-6) + 490*a(n-7) - 164*a(n-8) + 24*a(n-9).
Empirical g.f.: x*(4213 - 43871*x + 191076*x^2 - 458178*x^3 + 668501*x^4 - 617575*x^5 + 358558*x^6 - 119604*x^7 + 17496*x^8) / ((1 - x)^5*(1 - 2*x)^3*(1 - 3*x)). - Colin Barker, Nov 23 2018
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EXAMPLE
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Some solutions for n=4:
2 1 1 0 0 2 2 0 0 0 2 1 0 0 0 2 2 2 0 0
2 2 2 1 2 2 2 0 0 0 2 1 0 0 0 1 1 1 1 1
1 1 1 0 1 2 2 1 2 2 2 2 1 1 1 0 0 0 0 0
1 1 1 1 2 1 1 0 1 1 1 1 0 0 0 0 0 0 0 1
1 1 1 1 2 1 1 1 2 2 1 2 1 1 1 0 0 0 0 1
1 1 1 1 2 1 1 1 2 2 1 2 1 1 2 1 1 1 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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