A195763 Number of triangular nXnXn 0..n 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, 379137552

Offset

1,4

Comments

Diagonal 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..........1.1..........2.0..........2.0..........2.0
.....0.1.2........2.0.1........1.1.1........1.0.2........0.0.3........2.0.1
....1.1.1.1......0.0.3.1......2.1.1.0......1.3.0.0......1.2.1.0......0.0.1.3
...2.2.1.0.0....2.3.0.0.0....0.0.1.2.2....0.0.0.3.2....1.2.0.1.1....0.3.2.0.0
..1.0.0.2.2.1..1.0.0.2.2.1..1.2.1.1.0.1..1.2.2.0.0.1..1.1.0.2.1.1..1.2.0.0.2.1

Crossrefs

Sequence in context: A195765 A195766 A195767 * A265460 A137223 A159640

Adjacent sequences: A195760 A195761 A195762 * A195764 A195765 A195766

Keyword

nonn

Author

R. H. Hardin Sep 23 2011

Status

approved