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.

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

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

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

Adjacent sequences: A231410 A231411 A231412 * A231414 A231415 A231416

Keyword

nonn

Author

R. H. Hardin, Nov 08 2013

Status

approved