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A318019
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Number of nX3 0..1 arrays with every element unequal to 0, 1, 2 or 4 horizontally, vertically or antidiagonally adjacent elements, with upper left element zero.
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1
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4, 14, 45, 133, 419, 1382, 4495, 14754, 48525, 159584, 524981, 1727658, 5685321, 18710300, 61576790, 202655046, 666960573, 2195053580, 7224214965, 23775889227, 78249787781, 257531127865, 847571571085, 2789478970713, 9180573908293
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OFFSET
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1,1
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COMMENTS
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Column 3 of A318024.
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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) = 3*a(n-1) +4*a(n-2) -5*a(n-3) -14*a(n-4) -17*a(n-5) +18*a(n-6) +29*a(n-7) +23*a(n-8) +12*a(n-9) -27*a(n-10) -27*a(n-11) -16*a(n-12) -7*a(n-13) -5*a(n-14) +18*a(n-15) -9*a(n-16) +9*a(n-17) -3*a(n-18) for n>23
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EXAMPLE
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Some solutions for n=5
..0..1..1. .0..0..0. .0..1..1. .0..1..1. .0..0..1. .0..1..0. .0..1..1
..1..1..0. .0..1..0. .1..1..0. .1..1..1. .0..1..1. .0..0..0. .0..1..0
..1..0..0. .1..1..0. .1..1..1. .0..1..1. .1..1..0. .0..0..0. .0..0..0
..0..0..1. .1..1..0. .1..1..1. .1..1..1. .1..1..1. .0..0..1. .0..0..0
..0..1..1. .1..1..0. .1..1..1. .1..0..1. .1..0..1. .0..0..0. .0..0..0
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CROSSREFS
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Cf. A318024.
Sequence in context: A208666 A125068 A184138 * A182902 A108765 A304068
Adjacent sequences: A318016 A318017 A318018 * A318020 A318021 A318022
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KEYWORD
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nonn
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AUTHOR
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R. H. Hardin, Aug 12 2018
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STATUS
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approved
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