A201426 Number of nX2 0..2 arrays with rows and columns lexicographically nondecreasing and the instance counts of every value within one of each other

3, 11, 13, 76, 160, 111, 560, 955, 539, 2447, 3717, 1873, 7920, 11174, 5237, 21055, 28217, 12573, 48685, 62818, 26965, 101426, 127110, 53017, 194865, 238629, 97285, 350910, 421718, 168763, 599302, 709093, 279423, 979289, 1143571, 444809, 1541462

Offset

1,1

Comments

Column 2 of A201432

Links

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

Formula

Empirical: a(n) = 7*a(n-3) -21*a(n-6) +35*a(n-9) -35*a(n-12) +21*a(n-15) -7*a(n-18) +a(n-21)

Example

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

Crossrefs

Sequence in context: A083992 A370488 A105290 * A158790 A176049 A228237

Adjacent sequences: A201423 A201424 A201425 * A201427 A201428 A201429

Keyword

nonn

Author

R. H. Hardin Dec 01 2011

Status

approved