A201446 Number of nX3 0..3 arrays with every row and column nondecreasing rightwards and downwards, and the number of instances of each value within one of each other

4, 21, 52, 29, 246, 701, 844, 426, 2478, 5990, 6334, 2358, 13766, 29096, 26976, 9735, 50294, 100963, 89428, 29011, 149198, 283043, 237216, 75948, 368044, 680922, 557638, 169158, 816740, 1464838, 1163616, 350485, 1633894, 2887309, 2261850

Offset

1,1

Comments

Column 3 of A201451

Links

R. H. Hardin, Table of n, a(n) for n = 1..164

Formula

Empirical: a(n) = 2*a(n-4) +3*a(n-8) -8*a(n-12) -a(n-16) +10*a(n-20) -5*a(n-24) +5*a(n-32) -10*a(n-36) +a(n-40) +8*a(n-44) -3*a(n-48) -2*a(n-52) +a(n-56)

Example

Some solutions for n=10
..0..0..2....0..0..0....0..0..0....0..0..2....0..0..0....0..0..0....0..0..1
..0..0..2....0..0..1....0..0..0....0..1..2....0..0..1....0..1..2....0..1..1
..0..1..2....0..0..2....0..0..1....0..1..2....0..1..2....0..1..2....0..1..2
..0..1..3....1..1..3....1..1..2....0..1..2....0..2..3....0..1..2....0..2..2
..0..1..3....1..1..3....1..1..2....0..1..2....1..2..3....0..1..2....0..2..2
..0..1..3....1..1..3....1..2..2....0..1..2....1..2..3....1..1..2....0..2..3
..1..2..3....1..2..3....1..2..2....1..1..3....1..2..3....1..3..3....0..2..3
..1..2..3....2..2..3....2..3..3....1..2..3....1..2..3....2..3..3....1..2..3
..1..2..3....2..2..3....3..3..3....3..3..3....1..2..3....2..3..3....1..3..3
..2..2..3....2..2..3....3..3..3....3..3..3....1..3..3....2..3..3....1..3..3

Crossrefs

Sequence in context: A317225 A273780 A033569 * A371311 A220772 A242135

Adjacent sequences: A201443 A201444 A201445 * A201447 A201448 A201449

Keyword

nonn

Author

R. H. Hardin Dec 01 2011

Status

approved