A166201 Number of nXnXn triangular nonnegative integer arrays, symmetric under 120 degree rotation, with all sums of an element and its neighbors <= 6

1, 7, 3, 7, 66, 218, 1340, 25771, 157803, 2661967, 140020892, 1770255356, 73044448611, 8966527587527, 317675182498031

Offset

0,2

Links

Table of n, a(n) for n=0..14.

Example

Some solutions for n=4
.....1........2........0........1........0........4........3........1...
....0.0......0.0......1.0......0.1......1.1......0.0......1.0......1.0..
...0.5.0....0.1.0....0.1.1....1.1.0....1.0.1....0.0.0....0.1.1....0.3.1.
..1.0.0.1..2.0.0.2..0.1.0.0..1.0.1.1..0.1.1.0..4.0.0.4..3.1.0.3..1.1.0.1
------
.....0........0........4........3........1........3........0........3...
....0.0......0.0......0.0......0.1......1.0......1.0......0.0......1.1..
...0.4.0....0.3.0....0.1.0....1.1.0....0.1.1....0.0.1....0.6.0....1.0.1.
..0.0.0.0..0.0.0.0..4.0.0.4..3.0.1.3..1.1.0.1..3.1.0.3..0.0.0.0..3.1.1.3

Crossrefs

Sequence in context: A247950 A256844 A346538 * A248281 A111197 A245645

Adjacent sequences: A166198 A166199 A166200 * A166202 A166203 A166204

Keyword

nonn

Author

R. H. Hardin Oct 09 2009

Status

approved