A154032 Number of planar triangular n X n X n nonnegative integer grids symmetric under 120 degree rotation with every similarly oriented 2 X 2 X 2 subtriangle summing to 3.

1, 2, 10, 2, 3, 11, 3, 2, 12, 2, 3, 11, 3, 2, 12, 2, 3, 11, 3, 2, 12, 2, 3, 11, 3, 2, 12, 2, 3, 11, 3, 2, 12, 2, 3, 11, 3, 2, 12, 2, 3, 11, 3, 2, 12, 2, 3, 11, 3, 2, 12, 2, 3, 11, 3, 2, 12, 2, 3

Offset

2,2

Comments

Pattern 2 3 11 3 2 12 starts at n=5 and continues through at least n=60.

Links

Table of n, a(n) for n=2..60.

Example

Maximal zeros solution for n=11
............3
...........0.0
..........2.1.2
.........0.1.1.0
........2.1.1.1.2
.......0.1.1.1.1.0
......2.1.1.1.1.1.2
.....0.1.1.1.1.1.1.0
....2.1.1.1.1.1.1.1.2
...0.1.1.1.1.1.1.1.1.0
..3.0.2.0.2.0.2.0.2.0.3

Crossrefs

Sequence in context: A069287 A215749 A102775 * A221551 A010700 A121521

Adjacent sequences: A154029 A154030 A154031 * A154033 A154034 A154035

Keyword

nonn

Author

R. H. Hardin Jan 04 2009

Status

approved