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A207009 Number of n X 2 0..2 arrays avoiding the patterns z z+1 z or z z-1 z in any row or column. 3
9, 81, 529, 3721, 25921, 180625, 1256641, 8743849, 60855601, 423577561, 2948164209, 20519130025, 142812189025, 993971114361, 6918041467089, 48149568342121, 335120802753025, 2332439189580889, 16233767034063601 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
COMMENTS
Column 2 of A207015.
LINKS
FORMULA
Empirical: a(n) = 7*a(n-1) -6*a(n-2) +22*a(n-3) +114*a(n-4) +104*a(n-5) -184*a(n-6) -352*a(n-7) -128*a(n-8) -64*a(n-9) +32*a(n-10).
a(n) = A207008(n)^2. - Mark van Hoeij, May 14 2013
EXAMPLE
Some solutions for n=4
..1..0....2..0....1..2....0..2....0..1....0..1....2..0....2..2....0..2....0..2
..1..1....1..2....2..2....0..0....2..1....2..1....0..2....2..1....0..2....2..2
..0..1....0..2....2..2....0..1....2..2....2..0....1..0....2..1....2..2....0..0
..2..0....2..0....2..2....2..1....0..0....0..2....1..2....0..2....0..2....2..1
CROSSREFS
Sequence in context: A270295 A214618 A343462 * A196986 A293889 A218268
KEYWORD
nonn
AUTHOR
R. H. Hardin, Feb 14 2012
STATUS
approved

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Last modified April 15 23:50 EDT 2024. Contains 371696 sequences. (Running on oeis4.)