A242469 Number of length n+2 0..6 arrays with no three equal elements in a row and new values 0..6 introduced in 0..6 order

4, 12, 41, 159, 685, 3232, 16497, 90075, 520248, 3143900, 19678699, 126480319, 828889655, 5508880129, 36980189248, 249999755818, 1698491520413, 11579658486155, 79137696973965, 541762392142995, 3713215153801152

Offset

1,1

Comments

Column 6 of A242472

Links

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

Formula

Empirical: a(n) = 16*a(n-1) -79*a(n-2) +70*a(n-3) +361*a(n-4) -372*a(n-5) -964*a(n-6) +144*a(n-7) +1116*a(n-8) +720*a(n-9) +144*a(n-10)

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....0....1....1....1....1....1....1....0....1....1....1....1
..2....2....2....2....1....2....2....0....2....2....2....1....1....2....2....1
..3....1....3....3....1....0....3....2....0....3....0....0....2....1....0....2
..4....3....2....3....2....3....0....3....0....1....2....2....0....3....2....0
..3....4....4....4....3....0....3....2....1....1....1....1....0....3....3....1

Crossrefs

Sequence in context: A149343 A225586 A242468 * A242470 A242471 A239800

Adjacent sequences: A242466 A242467 A242468 * A242470 A242471 A242472

Keyword

nonn

Author

R. H. Hardin, May 15 2014

Status

approved