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A199834
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Number of -n..n arrays x(0..4) of 5 elements with zero sum and no two neighbors summing to zero
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1
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4, 114, 646, 2146, 5390, 11384, 21364, 36796, 59376, 91030, 133914, 190414, 263146, 354956, 468920, 608344, 776764, 977946, 1215886, 1494810, 1819174, 2193664, 2623196, 3112916, 3668200, 4294654, 4998114, 5784646, 6660546, 7632340, 8706784
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OFFSET
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1,1
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COMMENTS
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Row 3 of A199832
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LINKS
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R. H. Hardin, Table of n, a(n) for n = 1..200
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FORMULA
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Empirical: a(n) = (115/12)*n^4 - (29/6)*n^3 + (5/12)*n^2 - (7/6)*n.
Empirical: G.f.: -2*x*(2+47*x+58*x^2+8*x^3) / (x-1)^5. - R. J. Mathar, Aug 01 2014
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EXAMPLE
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Some solutions for n=3
..3....3....0....2....1....1....2...-1...-3...-2....0....0...-1...-1....2...-1
..2...-1...-3....1...-2....2....1....3...-3....0....3...-2...-2...-3...-1...-1
.-3....0....0....1....0...-1....0....0....1....3...-2....0....1...-2...-2...-3
..1...-1....1...-2...-1...-3...-2...-3....3....0....1....3....2....3....1....2
.-3...-1....2...-2....2....1...-1....1....2...-1...-2...-1....0....3....0....3
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CROSSREFS
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Sequence in context: A299394 A299222 A300036 * A194495 A260575 A275747
Adjacent sequences: A199831 A199832 A199833 * A199835 A199836 A199837
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KEYWORD
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nonn
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AUTHOR
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R. H. Hardin Nov 11 2011
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STATUS
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approved
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