A217504 Number of triangular nXnXn arrays of occupancy after each element either stays or moves to some neighbor and with no occupancy greater than 2

1, 7, 138, 8353, 1563486, 896267399, 1563576619949

Offset

1,2

Comments

Column 2 of A217510

Links

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

Example

Some solutions for n=4
.....1........1........0........1........1........1........2........1
....1.1......1.2......2.1......0.0......1.2......0.0......1.1......0.0
...0.1.2....2.2.0....2.0.1....2.0.1....0.2.2....1.1.2....1.1.0....1.2.1
..1.0.1.2..0.0.1.1..2.1.1.0..2.2.2.0..1.1.0.0..2.2.0.1..1.2.1.0..1.2.1.1

Crossrefs

Sequence in context: A009701 A120052 A171106 * A142295 A056254 A137463

Adjacent sequences: A217501 A217502 A217503 * A217505 A217506 A217507

Keyword

nonn

Author

R. H. Hardin Oct 05 2012

Status

approved