A208297 Number of nX3 nonnegative integer arrays with new values 0 upwards introduced in row major order and no element equal to any horizontal or antidiagonal neighbor (colorings ignoring permutations of colors)

2, 42, 2906, 433252, 113503692, 46538017584, 27700815674032, 22702140562948192, 24626774613248937584, 34296243004533645925408, 59839415643338575851475744, 128222446504879248765189962560, 331858429902640216546970620625280

Offset

1,1

Comments

Column 3 of A208301

Links

R. H. Hardin, Table of n, a(n) for n = 1..49

Example

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

Crossrefs

Sequence in context: A216336 A152286 A293864 * A278150 A193271 A193272

Adjacent sequences: A208294 A208295 A208296 * A208298 A208299 A208300

Keyword

nonn

Author

R. H. Hardin Feb 25 2012

Status

approved