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A204752
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Number of (n+2) X 8 0..1 arrays with every 3 X 3 subblock having three equal elements in a row horizontally, vertically, diagonally or antidiagonally exactly three ways, and new values 0..1 introduced in row major order.
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1
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590, 49, 48, 53, 61, 74, 95, 129, 184, 273, 417, 650, 1027, 1637, 2624, 4221, 6805, 10986, 17751, 28697, 46408, 75065, 121433, 196458, 317851, 514269, 832080, 1346309, 2178349, 3524618, 5702927, 9227505, 14930392, 24157857, 39088209
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OFFSET
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1,1
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COMMENTS
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LINKS
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FORMULA
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Empirical: a(n) = 2*a(n-1) - a(n-3) for n>5.
Empirical g.f.: x*(590 - 1131*x - 50*x^2 + 547*x^3 + 4*x^4) / ((1 - x)*(1 - x - x^2)). - Colin Barker, Jun 10 2018
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EXAMPLE
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Some solutions for n=3:
0 1 1 0 0 1 1 0 0 1 1 0 0 1 0 0 0 1 1 0 1 0 1 1
0 1 1 0 0 1 1 0 0 1 1 0 0 1 0 0 0 1 1 0 1 0 1 1
0 1 1 0 0 1 1 0 0 1 1 0 0 1 0 0 0 1 1 0 1 0 1 1
0 1 1 0 0 1 1 0 0 1 1 0 0 1 0 0 0 1 1 0 1 0 1 1
0 1 1 0 0 1 1 0 0 1 1 0 0 1 0 0 0 1 1 0 1 0 1 1
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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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