A209041 Number of n X 2 0..3 arrays with no element equal the average of immediate neighbors vertically above and horizontally left of it.

12, 124, 1300, 13644, 143212, 1503212, 15778340, 165616044, 1738375148, 18246711388, 191525101396, 2010327432972, 21101236121548, 221487384867980, 2324824070641124, 24402324144347820, 256136983080016460

Offset

1,1

Comments

Column 2 of A209047.

Links

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

Formula

Empirical: a(n) = 11*a(n-1) - 5*a(n-2) - 3*a(n-3).

Empirical g.f.: 4*x*(1 - x)*(3 + x) / (1 - 11*x + 5*x^2 + 3*x^3). - Colin Barker, Jul 08 2018

Example

Some solutions for n=4:
..3..1....1..0....2..3....1..0....1..2....0..1....0..1....2..3....1..3....2..0
..1..2....0..1....1..0....2..3....2..3....3..0....1..3....1..0....0..1....1..0
..3..3....1..3....3..2....1..3....3..0....1..1....3..0....0..3....1..0....2..0
..0..1....2..2....2..0....3..1....2..0....2..0....0..1....1..0....2..0....1..2

Crossrefs

Cf. A209047.

Sequence in context: A045507 A288350 A331396 * A155595 A070312 A153427

Adjacent sequences: A209038 A209039 A209040 * A209042 A209043 A209044

Keyword

nonn

Author

R. H. Hardin, Mar 04 2012

Status

approved