A164747 Number of nXnXn triangular 1..3 arrays with all 1s connected, all 2s connected, all 3s connected, 1 at the top vertex, 2 at the lower left, and 3 at the lower right, and no value having more than 5 identical values adjacent

1, 17, 171, 1928, 29840, 718188, 28564256

Offset

2,2

Links

Table of n, a(n) for n=2..8.

Example

Some solutions for n=4
......1..........1..........1..........1..........1..........1..........1....
.....2.2........1.3........3.3........1.1........2.1........3.1........3.1...
....2.3.2......1.1.3......2.2.3......1.3.3......2.2.3......3.3.3......3.1.3..
...2.3.3.3....2.1.3.3....2.3.3.3....2.2.3.3....2.2.3.3....2.3.3.3....2.3.3.3.
------
......1..........1..........1..........1..........1..........1..........1....
.....2.1........1.1........1.1........1.1........1.1........3.3........1.1...
....2.2.1......1.1.1......3.3.1......1.2.3......3.3.3......3.3.3......1.1.3..
...2.1.1.3....2.3.3.3....2.3.3.3....2.2.3.3....2.2.2.3....2.2.3.3....2.1.3.3.

Crossrefs

Sequence in context: A023015 A022645 A326211 * A166579 A142169 A142515

Adjacent sequences: A164744 A164745 A164746 * A164748 A164749 A164750

Keyword

nonn

Author

R. H. Hardin Aug 24 2009

Status

approved