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A230827
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Number of nX4 0..3 arrays x(i,j) with each element horizontally, vertically or antidiagonally next to at least one element with value (x(i,j)+1) mod 4 and at least one element with value (x(i,j)-1) mod 4, no adjacent elements equal, and upper left element zero
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1
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0, 6, 10, 62, 176, 734, 3034, 12962, 55806, 241462, 1047244, 4548392, 19770622, 85983476, 374071534, 1627718734, 7083554700, 30828250368, 134171670508, 583957263660, 2541594468334, 11062020222648, 48146469919922
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OFFSET
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1,2
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COMMENTS
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Column 4 of A230831
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LINKS
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R. H. Hardin, Table of n, a(n) for n = 1..210
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FORMULA
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Empirical: a(n) = 20*a(n-1) -174*a(n-2) +856*a(n-3) -2543*a(n-4) +4242*a(n-5) -1758*a(n-6) -8383*a(n-7) +18429*a(n-8) -9998*a(n-9) -19479*a(n-10) +35858*a(n-11) -3796*a(n-12) -44630*a(n-13) +26155*a(n-14) +46885*a(n-15) -36285*a(n-16) -52603*a(n-17) +27731*a(n-18) +62520*a(n-19) -8480*a(n-20) -68927*a(n-21) +7432*a(n-22) +63362*a(n-23) -4203*a(n-24) -57711*a(n-25) -41467*a(n-26) +16827*a(n-27) +61539*a(n-28) +68672*a(n-29) +13282*a(n-30) -105380*a(n-31) -115207*a(n-32) +42704*a(n-33) +133454*a(n-34) +42704*a(n-35) -68204*a(n-36) -61800*a(n-37) +6457*a(n-38) +32367*a(n-39) +12804*a(n-40) -4313*a(n-41) -5391*a(n-42) -1966*a(n-43) -339*a(n-44) -26*a(n-45) -a(n-46) for n>51
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EXAMPLE
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Some solutions for n=4
..0..1..0..1....0..3..2..3....0..1..3..2....0..1..2..0....0..1..2..0
..3..2..3..2....1..0..1..0....3..2..0..1....3..0..3..1....3..0..3..1
..0..1..0..1....2..3..2..3....0..1..3..2....2..1..2..3....2..1..2..3
..3..2..3..2....1..0..1..0....3..2..0..1....0..3..1..0....3..0..1..0
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CROSSREFS
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Sequence in context: A136849 A136847 A250106 * A111484 A119041 A105157
Adjacent sequences: A230824 A230825 A230826 * A230828 A230829 A230830
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KEYWORD
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nonn
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AUTHOR
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R. H. Hardin, Oct 30 2013
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STATUS
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approved
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