A155258 Number of ways to place zero or more nonadjacent 0,0 1,0 1,1 2,0 3,0 4,0 polyhexes in any orientation on a planar nXnXn triangular grid.

1, 7, 25, 90, 688, 4109, 25041, 287360, 3402527, 48602011, 1011814868, 22922047752

Offset

4,2

Links

Table of n, a(n) for n=4..15.

Example

Maximal 13 X 13 X 13 example
...............1
..............1.0
.............1.0.1
............1.0.1.1
...........1.1.0.0.1
..........0.0.0.0.0.1
.........1.0.1.1.0.0.1
........1.0.0.1.0.1.0.0
.......1.0.1.0.1.0.1.0.1
......1.0.1.1.0.1.0.1.0.1
.....1.1.0.0.1.0.1.0.1.0.1
....0.0.0.1.0.1.0.0.1.1.0.1
...1.1.1.1.1.0.1.0.0.0.0.1.1

Crossrefs

Sequence in context: A279216 A245769 A146933 * A261722 A256370 A199116

Adjacent sequences: A155255 A155256 A155257 * A155259 A155260 A155261

Keyword

nonn

Author

R. H. Hardin Jan 22 2009

Status

approved