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A206880
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Number of nX5 0..1 arrays avoiding 0 1 0 horizontally and 1 0 1 vertically
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1
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21, 441, 4705, 44879, 472412, 5179587, 56006452, 599130203, 6415489317, 68862978274, 739329103913, 7933883243105, 85128813219141, 913482746325836, 9802626037683613, 105191549603928895, 1128793872954895887
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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) -58*a(n-2) +347*a(n-3) +140*a(n-4) -530*a(n-5) +9303*a(n-6) -13514*a(n-7) -121746*a(n-8) -15323*a(n-9) +33707*a(n-10) +628740*a(n-11) +4819689*a(n-12) +602012*a(n-13) -24971113*a(n-14) -13357992*a(n-15) +40761516*a(n-16) +18020830*a(n-17) +237812*a(n-18) +65671414*a(n-19) -52609938*a(n-20) -104608842*a(n-21) -22319213*a(n-22) -34182852*a(n-23) +6860648*a(n-24) +108480290*a(n-25) +10214575*a(n-26) +135798774*a(n-27) -108129644*a(n-28) +67839752*a(n-29) -80003650*a(n-30) -10669415*a(n-31) +2001098*a(n-32) -14730061*a(n-33) +19683840*a(n-34) -5357218*a(n-35) +7501826*a(n-36) +833478*a(n-37) -2016577*a(n-38) +1994060*a(n-39) -1415538*a(n-40) +322598*a(n-41) +24377*a(n-42) -86458*a(n-43) +24377*a(n-44) +2403*a(n-45) -802*a(n-46) +255*a(n-47) -a(n-48) +20*a(n-49) -5*a(n-50) +a(n-51)
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EXAMPLE
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Some solutions for n=4
..1..1..0..1..1....0..1..1..1..0....1..0..1..1..0....1..0..1..1..0
..1..0..0..1..1....1..1..0..1..1....0..0..0..1..1....1..0..0..0..1
..0..0..1..1..1....1..0..0..1..1....0..0..0..1..1....0..0..0..0..0
..0..0..0..1..1....0..0..0..0..0....1..0..1..1..0....0..1..1..0..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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