A267928 Number of n X 1 0..3 arrays with every repeated value in every row and column greater than the previous repeated value.

4, 16, 60, 222, 804, 2872, 10132, 35383, 122480, 420752, 1435736, 4870132, 16432216, 55178416, 184481816, 614348813, 2038435340, 6740997616, 22223182372, 73053304378, 239502956924, 783241953896, 2555428926860, 8319101465587

Offset: 1

Author

R. H. Hardin, Jan 22 2016

Keywords

• nonn

Comments

Column 1 of A267933.

Examples

			Some solutions for n=8
..2....0....3....1....3....1....2....2....1....3....2....0....0....1....1....0
..1....1....1....2....2....0....1....2....0....1....3....1....0....1....1....3
..2....0....3....1....1....2....1....3....0....0....1....3....1....0....3....1
..0....0....0....2....3....0....2....3....2....3....2....1....0....1....1....2
..3....1....1....0....3....2....0....2....0....0....1....0....2....3....2....1
..1....1....2....3....1....1....2....0....2....2....1....2....0....3....3....2
..1....2....1....1....2....3....1....2....1....0....3....3....3....0....0....3
..3....3....1....3....3....1....0....0....3....3....0....0....1....3....3....3
		

Links

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

Crossrefs

Cf. A267933.

Formula

Empirical: a(n) = 12*a(n-1) - 48*a(n-2) + 44*a(n-3) + 150*a(n-4) - 252*a(n-5) - 216*a(n-6) + 324*a(n-7) + 243*a(n-8).

Empirical g.f.: x*(4 - 32*x + 60*x^2 + 94*x^3 - 284*x^4 - 152*x^5 + 388*x^6 + 259*x^7) / ((1 + x)^3*(1 - 3*x)^5). - Colin Barker, Feb 25 2018