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A251232
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Number of (n+1) X (4+1) 0..3 arrays with every 2 X 2 subblock summing to 6 and no 2 X 2 subblock having exactly two nonzero entries.
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1
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966, 1870, 3886, 8686, 20490, 50570, 129378, 340782, 918878, 2525262, 7049658, 19942026, 57058610, 164910430, 480976574, 1414571198, 4192696714, 12517386890, 37626434786, 113828691374, 346430157502, 1060262602062, 3261932440186
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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) = 13*a(n-1) -63*a(n-2) +122*a(n-3) +13*a(n-4) -371*a(n-5) +317*a(n-6) +308*a(n-7) -370*a(n-8) -144*a(n-9) +128*a(n-10) +48*a(n-11).
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EXAMPLE
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Some solutions for n=4:
..0..2..0..3..0....1..1..0..2..2....3..1..3..1..1....0..1..0..1..1
..1..3..1..2..1....2..2..3..1..1....0..2..0..2..2....2..3..2..3..1
..2..0..2..1..2....1..1..0..2..2....3..1..3..1..1....0..1..0..1..1
..3..1..3..0..3....1..3..2..2..0....1..1..1..1..3....2..3..2..3..1
..1..1..1..2..1....2..0..1..1..3....3..1..3..1..1....1..0..1..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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