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A234697
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Number of (n+1) X (1+1) 0..7 arrays with every 2 X 2 subblock having its diagonal sum differing from its antidiagonal sum by 5 (constant-stress 1 X 1 tilings).
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1
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408, 2628, 16848, 109224, 704160, 4594320, 29782080, 195532704, 1274237568, 8416415808, 55124437248, 366185867904, 2409750673920, 16093719394560, 106373608473600, 713965515692544, 4738136283260928, 31947371388453888
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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) + 90*a(n-2) - 540*a(n-3) - 2016*a(n-4) + 12096*a(n-5).
Empirical g.f.: 12*x*(34 + 15*x - 2970*x^2 - 672*x^3 + 64512*x^4) / ((1 - 6*x)*(1 - 42*x^2)*(1 - 48*x^2)). - Colin Barker, Oct 16 2018
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EXAMPLE
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Some solutions for n=4:
7 7 7 2 7 2 5 4 5 2 1 7 4 0 2 5 4 3 6 0
0 5 0 0 7 7 3 7 0 2 0 1 6 7 5 3 0 4 1 0
7 7 6 1 2 7 7 6 6 3 4 0 0 6 1 4 1 0 2 6
5 0 5 5 0 0 3 7 1 3 0 1 5 6 6 4 3 7 6 5
7 7 1 6 6 1 5 4 7 4 5 1 4 0 0 3 7 6 0 4
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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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