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A300423
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Number of nX4 0..1 arrays with every element equal to 1, 2 or 3 horizontally, vertically or antidiagonally adjacent elements, with upper left element zero.
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1
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2, 30, 272, 2227, 18205, 150352, 1240541, 10232500, 84410206, 696309062, 5743948074, 47382634074, 390866061898, 3224309862212, 26597791554069, 219408975139223, 1809935922730538, 14930419523386359, 123163159741496460
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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) = 9*a(n-1) +2*a(n-2) -67*a(n-3) -36*a(n-4) +250*a(n-5) +100*a(n-6) -337*a(n-7) -311*a(n-8) -4*a(n-9) +180*a(n-10) +1204*a(n-11) +368*a(n-12) -6713*a(n-13) +1814*a(n-14) +24164*a(n-15) -4030*a(n-16) -38947*a(n-17) +12663*a(n-18) +70432*a(n-19) -10144*a(n-20) -114955*a(n-21) -44953*a(n-22) +34295*a(n-23) -50431*a(n-24) -53119*a(n-25) +55368*a(n-26) +19801*a(n-27) -43336*a(n-28) -17045*a(n-29) -8457*a(n-30) -4910*a(n-31) +13442*a(n-32) +10577*a(n-33) +1491*a(n-34) +631*a(n-35) +1576*a(n-36) +8*a(n-37) -1962*a(n-38) -797*a(n-39) +165*a(n-40) +135*a(n-41) +129*a(n-42) +a(n-43) -24*a(n-44) -2*a(n-45) -a(n-46) +a(n-47) for n>49
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EXAMPLE
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Some solutions for n=5
..0..0..0..0. .0..0..0..1. .0..0..0..1. .0..0..0..1. .0..1..1..0
..0..1..1..0. .0..1..0..1. .0..1..0..1. .1..1..0..1. .0..1..0..1
..0..1..0..1. .0..1..0..0. .1..1..0..1. .0..1..0..1. .0..1..1..0
..1..0..1..1. .1..1..1..0. .0..1..0..1. .0..1..1..1. .1..0..0..0
..1..0..0..1. .0..0..0..0. .0..0..1..1. .0..0..0..1. .0..1..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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