A208170 Number of n X 3 0..3 arrays with new values 0..3 introduced in row major order and no element equal to more than one of its immediate leftward or upward neighbors.

5, 159, 8469, 473928, 26625693, 1496307201, 84091222866, 4725865313907, 265590215430897, 14925978329967384, 838829205068709369, 47141595663874099773, 2649323638611897879018, 148890075596000256587991

Offset

1,1

Comments

Column 3 of A208175.

Links

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

Formula

Empirical: a(n) = 62*a(n-1) - 333*a(n-2) + 396*a(n-3) - 135*a(n-4) for n>5.

Empirical g.f.: x*(5 - 151*x + 276*x^2 - 183*x^3 + 45*x^4) / ((1 - 5*x + 3*x^2)*(1 - 57*x + 45*x^2)). - Colin Barker, Jun 29 2018

Example

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

Crossrefs

Cf. A208175.

Sequence in context: A155208 A321529 A156486 * A088694 A208583 A197310

Adjacent sequences: A208167 A208168 A208169 * A208171 A208172 A208173

Keyword

nonn

Author

R. H. Hardin, Feb 24 2012

Status

approved