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A234265
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Number of (n+1) X (7+1) 0..2 arrays with every 2 X 2 subblock having its diagonal sum differing from its antidiagonal sum by 2 (constant-stress 1 X 1 tilings).
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1
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3104, 3746, 4924, 7304, 11876, 21164, 39508, 77060, 152564, 308756, 627124, 1294964, 2673716, 5617844, 11778868, 25220660, 53769524, 117585716, 255267124, 570940724, 1262696756, 2888073524, 6501509428, 15179569460, 34712242484
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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) = 3*a(n-1) + 6*a(n-2) - 24*a(n-3) + 4*a(n-4) + 36*a(n-5) - 24*a(n-6).
Empirical g.f.: 2*x*(1552 - 2783*x - 12469*x^2 + 22276*x^3 + 18954*x^4 - 33420*x^5) / ((1 - x)*(1 - 2*x)*(1 - 2*x^2)*(1 - 6*x^2)). - Colin Barker, Oct 14 2018
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EXAMPLE
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Some solutions for n=5:
0 2 2 0 0 2 0 2 2 2 0 0 0 2 0 0 0 0 2 0 0 2 2 2
0 0 2 2 0 0 0 0 2 0 0 2 0 0 0 2 2 0 0 0 2 2 0 2
2 0 0 2 2 0 2 0 0 0 2 2 2 0 2 2 0 0 2 0 0 2 2 2
2 2 0 0 2 2 2 2 2 0 0 2 0 0 0 2 2 0 0 0 2 2 0 2
0 2 2 0 0 2 0 2 2 2 0 0 0 2 0 0 2 2 0 2 2 0 0 0
2 2 0 0 2 2 2 2 0 2 2 0 2 2 2 0 2 0 0 0 2 2 0 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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