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A202080 Number of arrays of 9 integers in -n..n with sum zero and the sum of every adjacent pair being odd 1
6, 726, 8412, 80812, 340660, 1516410, 4213042, 12861252, 28421280, 69306670, 132493530, 278307730, 481381744, 909136644, 1461430338, 2548699638, 3874036128, 6350628468, 9236088510, 14409332790, 20220953874, 30295374604 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Row 7 of A202076

LINKS

R. H. Hardin, Table of n, a(n) for n = 1..210

FORMULA

Empirical: a(n) = a(n-1) +8*a(n-2) -8*a(n-3) -28*a(n-4) +28*a(n-5) +56*a(n-6) -56*a(n-7) -70*a(n-8) +70*a(n-9) +56*a(n-10) -56*a(n-11) -28*a(n-12) +28*a(n-13) +8*a(n-14) -8*a(n-15) -a(n-16) +a(n-17)

EXAMPLE

Some solutions for n=3

..0...-2...-2....2....2....2....2....2....0....0...-2...-2....2....0....0....2

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

.-2....2....0....2...-2....2...-2....0....2...-2...-2...-2....2....0....2....0

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

..0....0....2....0....2....0...-2....0...-2...-2....0...-2...-2...-2....2....0

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

.-2....0...-2...-2...-2...-2....0...-2...-2....2....2...-2....0....2....0...-2

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

..0...-2....0....0....0....0...-2...-2....2...-2...-2...-2....0....0...-2....2

CROSSREFS

Sequence in context: A168467 A080369 A036981 * A271528 A316748 A232130

Adjacent sequences:  A202077 A202078 A202079 * A202081 A202082 A202083

KEYWORD

nonn

AUTHOR

R. H. Hardin Dec 10 2011

STATUS

approved

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Last modified October 19 22:28 EDT 2018. Contains 316378 sequences. (Running on oeis4.)