A267960 Number of n X 1 0..2 arrays with every repeated value in every row and column greater than the previous repeated value.

3, 9, 24, 63, 159, 394, 957, 2292, 5419, 12678, 29385, 67560, 154215, 349770, 788741, 1769388, 3950499, 8782094, 19445313, 42898032, 94315743, 206709714, 451711869, 984397108, 2139750939, 4639901334, 10038505657, 21672089592, 46693408599

Offset: 1

Author

R. H. Hardin, Jan 22 2016

Keywords

• nonn

Comments

Column 1 of A267966.

Examples

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

Links

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

Crossrefs

Cf. A267966.

Formula

Empirical: a(n) = 6*a(n-1) - 9*a(n-2) - 8*a(n-3) + 24*a(n-4) - 16*a(n-6).

Conjectures from Colin Barker, Feb 25 2018: (Start)

G.f.: x*(3 - 9*x - 3*x^2 + 24*x^3 - 3*x^4 - 17*x^5) / ((1 + x)^2*(1 - 2*x)^4).

a(n) = (96*n + 2^n*(9*n*(n*(n+44)+445)+7622) + 640) / 7776 for n even.

a(n) = (2^n*(9*n*(n*(n+44)+445)+7622) - 32*(3*n+20)) / 7776 for n odd.

(End)