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A199709 Number of -n..n arrays x(0..6) of 7 elements with zero sum and no two neighbors equal 1
56, 2642, 27854, 149942, 559028, 1643204, 4099204, 9059092, 18251656, 34171380, 60292468, 101279218, 163252890, 254042820, 383508158, 563826638, 809873706, 1139548482, 1574209250, 2139036592, 2863528108, 3781894246, 4933615190 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Row 7 of A199704

LINKS

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

FORMULA

Empirical: a(n)=2*a(n-1)-a(n-3)-a(n-5)+a(n-6)-2*a(n-7)+2*a(n-8)+a(n-9)-a(n-13)-2*a(n-14)+2*a(n-15)-a(n-16)+a(n-17)+a(n-19)-2*a(n-21)+a(n-22)

EXAMPLE

Some solutions for n=5

.-4....2...-5....0...-4...-4...-5....0....1....1....0...-5....2...-5....1....2

..1...-5....2....2....1....2....1...-5....0...-5...-4....0...-5....0...-4....1

..5....3...-1...-2....4...-1....4...-3....3....1....4....4...-4....3...-3....2

..4....4....5....4...-4....3....2....1...-1....3...-1...-5....4....1....2...-1

.-1....3...-3....2....4...-1....5....2...-2...-2...-2...-1....2....3....5...-5

.-4...-4...-2...-5....1....2...-5....1....3...-1....5....4...-1...-2....0...-1

.-1...-3....4...-1...-2...-1...-2....4...-4....3...-2....3....2....0...-1....2

CROSSREFS

Sequence in context: A124101 A198948 A003696 * A205227 A224176 A223868

Adjacent sequences:  A199706 A199707 A199708 * A199710 A199711 A199712

KEYWORD

nonn

AUTHOR

R. H. Hardin Nov 09 2011

STATUS

approved

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Last modified July 22 16:42 EDT 2019. Contains 325225 sequences. (Running on oeis4.)