A242468 Number of length n+2 0..5 arrays with no three equal elements in a row and new values 0..5 introduced in 0..5 order.

4, 12, 41, 159, 684, 3204, 16042, 84412, 460174, 2570411, 14593499, 83749169, 484000704, 2809880001, 16360962717, 95445840289, 557493277222, 3258874744858, 19059827706050, 111510210083018, 652534784892188, 3819030330465099

Offset: 1

Author

R. H. Hardin, May 15 2014

Keywords

• nonn

Examples

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

Links

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

Crossrefs

Column 5 of A242472.

Formula

Empirical: a(n) = 11*a(n-1) - 30*a(n-2) - 21*a(n-3) + 112*a(n-4) + 63*a(n-5) - 119*a(n-6) - 120*a(n-7) - 30*a(n-8).

Empirical g.f.: x*(4 - 32*x + 29*x^2 + 152*x^3 - 31*x^4 - 285*x^5 - 215*x^6 - 49*x^7) / ((1 - x - x^2)*(1 - 2*x - 2*x^2)*(1 - 3*x - 3*x^2)*(1 - 5*x - 5*x^2)). - Colin Barker, Nov 01 2018