A192766 Number of n X n symmetric 0..3 arrays with each element equal to at least one horizontal or vertical neighbor, containing at least one 3 and with new values 0..3 introduced in lower triangular row major order

0, 0, 0, 17, 7720, 4829792, 6716752296, 25512182673851, 280268522844817397, 9139496699518220983774, 891049711767000782484301987

Offset

1,4

Links

Table of n, a(n) for n=1..11.

Example

Some solutions for 5X5
..0..0..2..2..3....0..0..1..2..2....0..0..1..1..0....0..0..1..3..0
..0..1..1..3..3....0..1..1..3..1....0..1..1..2..0....0..0..1..3..0
..2..1..1..1..1....1..1..1..3..1....1..1..2..2..3....1..1..2..2..3
..2..3..1..0..0....2..3..3..1..1....1..2..2..3..3....3..3..2..3..3
..3..3..1..0..0....2..1..1..1..1....0..0..3..3..3....0..0..3..3..3

Crossrefs

Sequence in context: A287038 A198406 A198533 * A166326 A203678 A257044

Adjacent sequences: A192763 A192764 A192765 * A192767 A192768 A192769

Keyword

nonn

Author

R. H. Hardin Jul 09 2011

Status

approved