A195765 Number of triangular nXnXn 0..3 arrays with all row sums equal to the length of the row and all diagonal sums equal to the length of the respective diagonal

1, 1, 1, 3, 18, 228, 8472, 898125, 276763188

Offset

1,4

Comments

Column 3 of A195768

Links

Table of n, a(n) for n=1..9.

Example

Some solutions for n=6
.......1............1............1............1............1............1
......1.1..........0.2..........0.2..........1.1..........0.2..........2.0
.....1.2.0........2.0.1........1.2.0........3.0.0........0.2.1........1.0.2
....1.1.0.2......1.0.3.0......1.0.2.1......0.0.2.2......2.0.2.0......1.1.2.0
...1.0.2.1.1....1.2.0.1.1....2.1.1.0.1....0.2.1.1.1....2.1.1.0.1....0.2.0.1.2
..1.1.2.0.1.1..1.1.0.2.1.1..1.0.1.2.1.1..1.2.1.0.1.1..1.0.0.3.1.1..1.2.0.2.0.1

Crossrefs

Sequence in context: A340336 A222686 A274271 * A195766 A195767 A195763

Adjacent sequences: A195762 A195763 A195764 * A195766 A195767 A195768

Keyword

nonn

Author

R. H. Hardin Sep 23 2011

Status

approved