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A181260
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Number of (n+2)X8 binary matrices with every 3X3 block having exactly four 1's
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2
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21024, 27554, 36244, 48846, 79324, 133850, 242784, 526226, 1196428, 2877078, 7542964, 20219426, 55452024, 157207034, 449767204, 1298801406, 3801296524, 11170281290, 32957815824, 97800035426, 290736856828, 865851794598
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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)=6*a(n-1)-11*a(n-2)+42*a(n-3)-216*a(n-4)+396*a(n-5)-719*a(n-6)+3018*a(n-7)-5533*a(n-8)+6498*a(n-9)-20880*a(n-10)+38280*a(n-11)-33444*a(n-12)+75384*a(n-13)-138204*a(n-14)+97848*a(n-15)-134784*a(n-16)+247104*a(n-17)-150336*a(n-18)+93312*a(n-19)-171072*a(n-20)+93312*a(n-21)
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EXAMPLE
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Some solutions for 4X8
..0..1..0..1..1..0..1..0....1..1..0..1..0..0..1..1....1..1..0..1..1..0..1..1
..1..0..0..0..0..0..0..0....1..0..1..1..1..1..0..0....0..0..0..0..0..0..0..1
..1..0..1..1..0..1..1..1....0..0..0..0..0..0..1..0....1..1..0..1..1..0..1..0
..0..1..0..1..1..0..1..0....0..1..1..0..0..1..0..1....1..1..0..1..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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