A195767 Number of triangular nXnXn 0..5 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, 8904, 1039761, 379119168

Offset

1,4

Comments

Column 5 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..........1.1..........1.1..........1.1..........1.1..........0.2
.....0.3.0........1.0.2........3.0.0........1.2.0........1.1.1........1.2.0
....1.1.1.1......2.1.0.1......0.0.2.2......1.0.2.1......1.1.2.0......1.1.1.1
...2.0.1.0.2....0.1.2.2.0....0.2.1.1.1....1.1.1.0.2....1.1.0.1.2....2.0.1.1.1
..1.0.2.2.0.1..1.2.0.0.2.1..1.2.1.0.1.1..1.1.1.2.0.1..1.1.1.2.0.1..1.0.2.1.1.1

Crossrefs

Sequence in context: A274271 A195765 A195766 * A195763 A265460 A137223

Adjacent sequences: A195764 A195765 A195766 * A195768 A195769 A195770

Keyword

nonn

Author

R. H. Hardin Sep 23 2011

Status

approved