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

1,1

Comments

Column 1 of A267933.

Links

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

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

Example

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

Crossrefs

Cf. A267933.

Sequence in context: A273347 A268939 A269635 * A269532 A269673 A231896

Adjacent sequences: A267925 A267926 A267927 * A267929 A267930 A267931

Keyword

nonn

Author

R. H. Hardin, Jan 22 2016

Status

approved