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A197051
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Number of nX5 0..4 arrays with each element equal to the number its horizontal and vertical zero neighbors.
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3
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4, 10, 38, 108, 358, 1132, 3580, 11382, 36270, 114992, 365628, 1162290, 3692624, 11733828, 37293892, 118504546, 376583590, 1196750110, 3803034578, 12085297922, 38405269512, 122045123484, 387837623386, 1232482503260, 3916616317912
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OFFSET
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1,1
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COMMENTS
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Every 0 is next to 0 0's, every 1 is next to 1 0's, every 2 is next to 2 0's, every 3 is next to 3 0's, every 4 is next to 4 0's.
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LINKS
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FORMULA
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Empirical: a(n) = a(n-1) +4*a(n-2) +10*a(n-3) +4*a(n-4) -20*a(n-5) +a(n-6) -2*a(n-7) +2*a(n-8) -16*a(n-9) +4*a(n-10) +a(n-13) for n>14.
Equivalent empirical g.f. 4*x -2*x^2*(5+14*x+15*x^2-x^3-39*x^4-8*x^5+6*x^6-21*x^7-13*x^8-x^9+x^10+3*x^11+3*x^12) ) / ( -1+x+4*x^2+10*x^3+4*x^4-20*x^5+x^6-2*x^7+2*x^8-16*x^9+4*x^10+x^13 ). - R. J. Mathar, Oct 10 2011
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EXAMPLE
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Some solutions for n=4
..0..1..2..0..2....1..1..0..3..0....0..3..0..3..0....0..2..1..0..2
..2..1..0..4..0....0..2..2..0..3....3..0..3..0..2....2..0..2..2..0
..0..1..3..0..3....3..0..2..2..0....0..2..1..1..1....1..2..0..2..1
..1..1..0..3..0....0..3..0..1..1....1..1..0..2..0....0..1..2..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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