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A260469
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Number of (n+2)X(2+2) 0..1 arrays with each 3X3 subblock having clockwise perimeter pattern 00000000 00000001 or 00010101
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1
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49, 92, 213, 471, 1085, 2562, 5891, 13530, 31372, 72451, 166919, 385563, 890572, 2054927, 4743628, 10953016, 25283529, 58363941, 134740753, 311052242, 718052661, 1657646568, 3826724610, 8834001277, 20393409965, 47078589297
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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) = a(n-1) +a(n-2) +5*a(n-3) +a(n-4) -3*a(n-5) -3*a(n-6) +a(n-7) +2*a(n-8) -a(n-9) -5*a(n-10) -5*a(n-11) -2*a(n-15) -2*a(n-16) for n>17
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EXAMPLE
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Some solutions for n=4
..0..0..0..0....0..0..0..1....0..0..0..0....0..0..0..1....0..0..0..1
..1..0..0..1....1..0..0..0....0..0..0..1....1..0..0..0....0..0..1..0
..0..0..0..0....0..0..0..0....0..0..0..0....0..0..0..0....0..0..0..0
..0..0..0..0....0..0..0..0....0..0..0..0....0..0..0..1....0..0..0..0
..0..0..0..1....0..0..1..0....0..0..0..0....0..0..0..0....1..0..0..0
..0..0..0..0....0..0..0..0....0..0..0..1....0..1..0..1....0..0..0..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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