A154076 Number of planar triangular n X n X n nonnegative integer grids symmetric both under 120 degree rotation and reflection with every similarly oriented 5 X 5 X 5 subtriangle summing to 9.

13, 19, 34, 21, 7, 16, 7, 1, 5, 3, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1

Offset

5,1

Comments

Value 1 starts at n=15 and continues through at least n=56.

Links

Table of n, a(n) for n=5..56.

Example

Maximal zeros solution for n=15
................1
...............0.0
..............1.1.1
.............0.1.1.0
............1.0.1.0.1
...........1.1.0.0.1.1
..........0.0.0.3.0.0.0
.........1.1.1.0.0.1.1.1
........0.1.1.0.1.0.1.1.0
.......1.0.1.0.1.1.0.1.0.1
......1.1.0.0.1.1.1.0.0.1.1
.....0.0.0.3.0.0.0.0.3.0.0.0
....1.1.1.0.0.1.1.1.0.0.1.1.1
...0.1.1.0.1.0.1.1.0.1.0.1.1.0
..1.0.1.0.1.1.0.1.0.1.1.0.1.0.1

Crossrefs

Sequence in context: A279426 A241120 A128342 * A275660 A088186 A089490

Adjacent sequences: A154073 A154074 A154075 * A154077 A154078 A154079

Keyword

nonn

Author

R. H. Hardin Jan 04 2009

Status

approved