A204677 Number of n X n 0..3 arrays with no occurrence of three equal elements in a row horizontally, vertically, diagonally or antidiagonally, and new values 0..3 introduced in row major order.

1, 15, 6451, 40919141, 2579588216958

Offset

1,2

Comments

Diagonal of A204685.

Links

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

Example

Some solutions for n=5
..0..1..1..0..2....0..0..1..1..0....0..0..1..0..2....0..0..1..0..0
..2..3..1..3..3....2..0..3..3..0....2..1..1..3..2....0..2..3..1..1
..0..0..3..2..3....2..3..1..0..3....0..1..0..3..3....2..0..1..0..0
..3..2..0..1..2....0..3..2..1..0....2..2..3..2..0....0..0..3..0..1
..0..3..3..1..2....2..2..3..0..0....1..0..3..3..2....1..2..1..3..2

Crossrefs

Cf. A204685.

Sequence in context: A296177 A206360 A292972 * A198250 A066968 A113795

Adjacent sequences: A204674 A204675 A204676 * A204678 A204679 A204680

Keyword

nonn

Author

R. H. Hardin, Jan 18 2012

Status

approved