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A235273
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Number of (n+1) X (3+1) 0..4 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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208, 380, 632, 1280, 2344, 5096, 10088, 23000, 48328, 113720, 249512, 599480, 1355464, 3301496, 7618088, 18722360, 43787848, 108247160, 255425192, 633863480, 1504419784, 3742789496, 8917090088, 22221233720, 53073853768, 132403182200
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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) = a(n-1) + 15*a(n-2) - 15*a(n-3) - 80*a(n-4) + 80*a(n-5) + 180*a(n-6) - 180*a(n-7) - 144*a(n-8) + 144*a(n-9).
Empirical g.f.: 4*x*(52 + 43*x - 717*x^2 - 483*x^3 + 3481*x^4 + 1698*x^5 - 7062*x^6 - 1872*x^7 + 5040*x^8) / ((1 - x)*(1 - 2*x)*(1 + 2*x)*(1 - 2*x^2)*(1 - 3*x^2)*(1 - 6*x^2)). - Colin Barker, Oct 18 2018
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EXAMPLE
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Some solutions for n=4:
3 0 2 0 4 2 4 2 3 0 3 0 4 2 4 2 4 0 4 2
1 3 0 3 0 3 0 3 0 2 0 2 1 4 1 4 1 2 1 4
4 1 3 1 2 0 2 0 3 0 3 0 3 1 3 1 4 0 4 2
1 3 0 3 1 4 1 4 0 2 0 2 0 3 0 3 0 1 0 3
3 0 2 0 2 0 2 0 4 1 4 1 2 0 2 0 4 0 4 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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