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A204363
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Number of (n+2)X3 0..2 arrays with every 3X3 subblock having three equal elements in a row horizontally, vertically or nw-to-se diagonally exactly three ways, and new values 0..2 introduced in row major order
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1
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74, 212, 555, 891, 2419, 6121, 13693, 38041, 99753, 256077, 702265, 1904821, 5140593, 14093533, 38567033, 105514613, 289594209, 794670109, 2180840713, 5989829701, 16450772689, 45183870253, 124126578969, 340996458069
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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) = 5*a(n-1) -7*a(n-2) +3*a(n-3) -6*a(n-4) +12*a(n-5) +14*a(n-6) -84*a(n-7) +164*a(n-8) -292*a(n-9) +392*a(n-10) -392*a(n-11) +640*a(n-12) -896*a(n-13) +64*a(n-14) +2176*a(n-15) -3584*a(n-16) +2304*a(n-17) -512*a(n-18)
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EXAMPLE
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Some solutions for n=5
..0..0..1....0..0..0....0..0..0....0..0..1....0..0..1....0..0..1....0..1..2
..1..0..0....0..0..0....1..1..1....0..0..0....1..1..1....2..0..2....2..2..2
..0..0..0....0..1..1....2..2..2....0..0..1....1..1..1....0..0..0....2..2..2
..2..0..0....0..0..0....0..0..0....1..0..0....2..2..2....0..0..0....2..1..1
..2..2..0....0..1..0....1..1..1....0..0..0....2..2..2....1..1..1....2..2..2
..2..2..2....0..1..0....1..1..1....1..0..0....1..2..1....0..0..0....2..0..2
..2..2..0....0..1..0....2..2..2....1..2..0....0..2..2....1..1..1....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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