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A234651
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Number of (n+1) X (1+1) 0..5 arrays with every 2 X 2 subblock having its diagonal sum differing from its antidiagonal sum by 4 (constant-stress 1 X 1 tilings).
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1
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160, 728, 3264, 15008, 67840, 315008, 1434624, 6722048, 30822400, 145614848, 671760384, 3197247488, 14829813760, 71052197888, 331140562944, 1595912880128, 7469054033920, 36183831216128, 169965785186304, 827149902675968
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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) = 4*a(n-1) + 44*a(n-2) - 176*a(n-3) - 480*a(n-4) + 1920*a(n-5).
Empirical g.f.: 8*x*(20 + 11*x - 836*x^2 - 240*x^3 + 8640*x^4) / ((1 - 4*x)*(1 - 20*x^2)*(1 - 24*x^2)). - Colin Barker, Oct 15 2018
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EXAMPLE
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Some solutions for n=5:
5 2 4 4 2 4 5 1 0 1 1 2 2 3 5 4 2 2 1 4
4 5 4 0 3 1 1 1 5 2 4 1 4 1 0 3 1 5 2 1
5 2 5 5 2 4 4 0 1 2 1 2 2 3 1 0 2 2 1 4
0 1 0 4 4 2 1 1 5 2 3 0 4 1 2 5 0 4 5 4
5 2 1 1 0 2 4 0 0 1 3 4 1 2 5 4 5 5 0 3
1 2 1 5 2 0 4 4 0 5 0 5 3 0 5 0 0 4 4 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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