A217505 Number of triangular n X n X n arrays of occupancy after each element either stays or moves to some neighbor and with no occupancy greater than 3.

1, 10, 306, 34489, 14162520, 21101953059, 113688398105827

Offset

1,2

Links

Table of n, a(n) for n=1..7.

Example

Some solutions for n=4:
.....0........0........2........0........0........0........2........1
....2.3......2.0......0.0......1.1......0.3......0.1......2.0......3.0
...2.0.2....0.2.0....3.1.0....2.0.2....1.3.3....0.1.2....2.0.0....1.0.2
..0.0.1.0..2.0.2.2..2.1.0.1..1.3.0.0..0.0.0.0..3.2.1.0..0.2.1.1..1.2.0.0

Crossrefs

Column 3 of A217510.

Sequence in context: A152165 A228188 A041425 * A379555 A222972 A119297

Adjacent sequences: A217502 A217503 A217504 * A217506 A217507 A217508

Keyword

nonn,more

Author

R. H. Hardin, Oct 05 2012

Status

approved