A184098 Number of n X n toroidal 0..2 arrays with each element having the sum of its vertical neighbors equal to the sum of its horizontal neighbors

3, 9, 87, 361, 1383, 7569, 20247, 126025, 299463, 1912689

Offset

1,1

Comments

Number of solutions in 0..2 of a 1-d velocity-one wave equation utt=uxx on a periodic grid

Diagonal of A184099

Links

Table of n, a(n) for n=1..10.

Example

Some solutions for 5X5
..0..1..1..1..0....1..2..1..2..0....0..2..1..2..1....2..1..1..0..1
..0..0..1..1..1....2..1..2..0..1....1..0..2..2..1....2..2..0..0..1
..1..0..0..1..1....1..2..0..1..2....1..1..1..1..2....1..1..1..1..1
..1..1..0..0..1....2..0..1..2..1....2..2..0..1..1....0..0..2..2..1
..1..1..1..0..0....0..1..2..1..2....2..1..2..0..1....0..1..1..2..1

Crossrefs

Sequence in context: A307799 A326159 A203559 * A249789 A067210 A018654

Adjacent sequences: A184095 A184096 A184097 * A184099 A184100 A184101

Keyword

nonn

Author

R. H. Hardin Jan 09 2011

Status

approved