A203021 Number of n X 3 nonnegative integer arrays with adjacent horizontal and vertical element pair sums equal to all values in 0..2nk-n-k-1 (each exactly once).

2, 36, 3216, 257664, 69822004

Offset

1,1

Comments

Column 3 of A203022.

Links

Table of n, a(n) for n=1..5.

Example

Some solutions for n=3
..0..1..7....0..2..8....7..1..4....4..6..0....1..7..0....0..1..4....9..0..1
..0..2..4....0..3..1....0..1..2....7..2..3....0..2..3....0..8..2....2..0..3
..4..3..6....1..5..6....0..9..2....0..0..1....0..4..7....4..3..0....5..5..3

Crossrefs

Cf. A203022.

Sequence in context: A178949 A200571 A213985 * A319507 A001070 A095229

Adjacent sequences: A203018 A203019 A203020 * A203022 A203023 A203024

Keyword

nonn

Author

R. H. Hardin, Dec 27 2011

Status

approved