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A221059
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Equals one maps: number of n X 3 binary arrays indicating the locations of corresponding elements equal to exactly one of their horizontal and antidiagonal neighbors in a random 0..3 n X 3 array.
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2
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4, 37, 323, 2735, 22683, 185563, 1503659, 12103019, 96951211, 773938571, 6162595115, 48980025803, 388763683179, 3082612373003, 24424875031211, 193423609703243, 1531129131726827, 12116710888585355, 95865381708690731
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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) = 11*a(n-1) - 10*a(n-2) - 104*a(n-3) - 80*a(n-4) - 8*a(n-5) - 32*a(n-6).
Empirical g.f.: x*(4 - 7*x - 44*x^2 - 32*x^3 - 4*x^4 - 16*x^5) / (1 - 11*x + 10*x^2 + 104*x^3 + 80*x^4 + 8*x^5 + 32*x^6). - Colin Barker, Mar 13 2018
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EXAMPLE
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Some solutions for n=3:
..1..0..0....0..0..0....0..0..1....1..0..0....1..1..0....0..0..0....1..1..0
..1..0..0....1..1..0....0..0..1....1..1..0....0..1..1....0..0..0....1..0..0
..1..1..0....0..1..1....1..1..0....0..0..1....0..0..0....1..0..1....0..1..0
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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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