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A235100
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Number of (n+1) X (1+1) 0..6 arrays with every 2 X 2 subblock having its diagonal sum differing from its antidiagonal sum by 4, with no adjacent elements equal (constant-stress tilted 1 X 1 tilings).
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1
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154, 670, 2900, 12578, 54530, 236496, 1025770, 4449942, 19307284, 83782730, 363623322, 1578383808, 6852296402, 29752369022, 129201632884, 561144450002, 2437478108882, 10589252938544, 46009511768922, 199934061184966
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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) = 7*a(n-1) - 2*a(n-2) - 47*a(n-3) + 3*a(n-4) + 84*a(n-5) + 36*a(n-6).
Empirical g.f.: 2*x*(77 - 204*x - 741*x^2 + 428*x^3 + 1656*x^4 + 648*x^5) / ((1 - 3*x - 6*x^2)*(1 - 4*x - 4*x^2 + 11*x^3 + 6*x^4)). - Colin Barker, Oct 17 2018
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EXAMPLE
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Some solutions for n=5:
0 1 0 3 3 1 2 4 6 1 5 2 3 2 0 6 0 2 6 4
1 6 2 1 4 6 4 2 3 2 2 3 2 5 3 5 5 3 1 3
4 5 3 6 6 4 6 0 0 3 0 5 4 3 0 6 3 5 6 4
5 2 1 0 1 3 3 1 5 4 2 3 6 1 2 4 0 6 4 6
4 5 0 3 4 2 4 6 6 1 0 5 3 2 4 2 1 3 2 0
1 6 5 4 1 3 3 1 3 2 1 2 1 4 3 5 2 0 1 3
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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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