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A199834 Number of -n..n arrays x(0..4) of 5 elements with zero sum and no two neighbors summing to zero 1
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 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Row 3 of A199832

LINKS

R. H. Hardin, Table of n, a(n) for n = 1..200

FORMULA

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

EXAMPLE

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

CROSSREFS

Sequence in context: A299394 A299222 A300036 * A194495 A260575 A275747

Adjacent sequences:  A199831 A199832 A199833 * A199835 A199836 A199837

KEYWORD

nonn

AUTHOR

R. H. Hardin Nov 11 2011

STATUS

approved

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Last modified May 19 18:35 EDT 2022. Contains 353847 sequences. (Running on oeis4.)