A267906 Number of n X 2 0..2 arrays with every repeated value in every row unequal to the previous repeated value, and in every column equal to the previous repeated value, and new values introduced in row-major sequential order.

2, 14, 122, 938, 6734, 45938, 302402, 1939154, 12192302, 75508538, 462161714, 2802600938, 16870221902, 100950439394, 601202522882, 3566576610338, 21091803794894, 124410954720938, 732300042558002, 4302980995610234

Offset: 1

Author

R. H. Hardin, Jan 22 2016

Keywords

• nonn

Comments

Column 2 of A267911.

Examples

			Some solutions for n=6:
..0..1....0..1....0..1....0..1....0..0....0..1....0..1....0..0....0..1....0..1
..0..2....2..2....1..1....0..0....1..1....1..0....2..0....1..2....2..2....2..2
..1..0....1..0....1..1....2..2....0..0....2..0....2..1....2..0....2..0....0..1
..2..1....0..0....0..2....1..1....1..1....2..0....2..2....1..0....1..2....1..2
..0..1....2..0....2..1....2..0....2..0....1..2....0..0....0..2....2..2....1..1
..0..1....0..2....1..1....1..2....0..1....2..1....2..2....1..0....2..1....0..1
		

Links

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

Crossrefs

Cf. A267911.

Formula

Empirical: a(n) = 14*a(n-1) - 60*a(n-2) + 50*a(n-3) + 145*a(n-4) - 80*a(n-5) - 84*a(n-6) + 16*a(n-7).

Empirical g.f.: 2*x*(1 - 7*x + 23*x^2 - 15*x^3 - 34*x^4 - 14*x^5 + 4*x^6) / ((1 - x)*(1 + x)*(1 - 4*x)*(1 - 6*x + x^2)*(1 - 4*x - 4*x^2)). - Colin Barker, Feb 25 2018