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A199839 Number of -n..n arrays x(0..9) of 10 elements with zero sum and no two neighbors summing to zero 1
138, 88636, 3685550, 51077518, 389832124, 2044221894, 8281149188, 27785393300, 80752300406, 209581305608, 496408914210, 1090354976530, 2248071267000, 4391976524034, 8191437222152, 14673108432136, 25367684178562 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Row 8 of A199832

LINKS

R. H. Hardin, Table of n, a(n) for n = 1..33

FORMULA

Empirical: a(n) = (124952/567)*n^9 - (35524/315)*n^8 + (50588/945)*n^7 - (2494/45)*n^6 + (13739/270)*n^5 - (1927/180)*n^4 - (41254/2835)*n^3 + (3319/420)*n^2 - (781/630)*n

EXAMPLE

Some.solutions.for.n=3

.-3...-3...-3...-3...-3...-3...-3...-3...-3...-3...-3...-3...-3...-3...-3...-3

.-3...-2...-3...-3...-2...-3...-2...-3...-3...-3...-3...-2...-3...-3...-3...-2

..2....0....2...-1...-3....1....1....0....1....0....2....0....1....1....2....1

..1...-1....3....2....1....1...-3....3...-2....2....0....1....1...-2....0....1

..1....3....3....2....1....3....2....2....3....3....1...-2....2....3...-1....3

..2...-1....2...-3....3....1....1....0....2....3....1....3....0....3....3....1

.-3....0....1....1....3....3....1....1....3....0....1...-2...-3....0....2...-2

..1....1....1....3....1....0....2...-2....0....1...-2....3....1....2....1...-2

..1....3...-3....0....1...-2....0....1...-2...-2....3....3....1...-1...-2....1

..1....0...-3....2...-2...-1....1....1....1...-1....0...-1....3....0....1....2

CROSSREFS

Sequence in context: A163693 A089518 A223192 * A005447 A261703 A266003

Adjacent sequences: A199836 A199837 A199838 * A199840 A199841 A199842

KEYWORD

nonn

AUTHOR

R. H. Hardin Nov 11 2011

STATUS

approved

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Last modified February 6 11:36 EST 2023. Contains 360104 sequences. (Running on oeis4.)