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

1,1

Links

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

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

Example

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

Crossrefs

Column 5 of A242472.

Sequence in context: A149342 A149343 A225586 * A242469 A242470 A242471

Adjacent sequences: A242465 A242466 A242467 * A242469 A242470 A242471

Keyword

nonn

Author

R. H. Hardin, May 15 2014

Status

approved