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A231413
Number of (n+1) X (1+1) 0..2 arrays with no element equal to a strict majority of its horizontal, diagonal and antidiagonal neighbors, with values 0..2 introduced in row major order.
4
9, 50, 285, 1617, 9188, 52193, 296511, 1684466, 9569425, 54363701, 308839124, 1754508933, 9967330587, 56624207962, 321681006005, 1827463435305, 10381783646596, 58978707645369, 335056872107879, 1903451466275938
OFFSET
1,1
COMMENTS
Column 1 of A231419.
LINKS
FORMULA
Empirical: a(n) = 6*a(n-1) - 11*a(n-3) + 4*a(n-4).
Empirical g.f.: x*(9 - 4*x - 15*x^2 + 6*x^3) / (1 - 6*x + 11*x^3 - 4*x^4). - Colin Barker, Feb 21 2018
EXAMPLE
Some solutions for n=5:
..0..1....0..0....0..1....0..1....0..0....0..1....0..1....0..1....0..1....0..1
..0..2....1..2....0..2....0..2....1..2....0..1....1..2....0..1....0..2....2..1
..0..1....1..2....0..1....0..1....0..1....1..2....0..2....1..0....2..1....2..0
..2..1....1..0....2..1....1..0....2..0....1..0....2..1....2..2....0..1....1..0
..2..0....1..2....0..2....2..0....1..2....2..2....2..0....0..1....1..2....1..0
..0..1....0..0....0..2....2..0....0..1....1..1....2..1....0..1....1..2....2..0
CROSSREFS
Cf. A231419.
Sequence in context: A369906 A257589 A341921 * A007681 A279972 A115366
KEYWORD
nonn
AUTHOR
R. H. Hardin, Nov 08 2013
STATUS
approved