A197041 Number of n X n 0..4 arrays with each element x equal to the number of its horizontal and vertical neighbors equal to 4,2,0,1,3 for x=0,1,2,3,4

1, 7, 120, 7407, 1563352, 1146653592, 2887590375825, 24713390632082079

Offset

1,2

Comments

Every 0 is next to 0 4's, every 1 is next to 1 2's, every 2 is next to 2 0's, every 3 is next to 3 1's, every 4 is next to 4 3's

Diagonal of A197047

Links

Table of n, a(n) for n=1..8.

Example

Some solutions for n=4
..2..0..1..0....0..0..2..1....2..0..0..0....0..2..0..0....0..2..2..0
..0..0..2..0....1..2..0..0....0..1..1..2....1..2..0..1....2..0..0..2
..0..0..1..0....1..2..0..0....0..2..0..0....0..0..0..2....1..1..0..2
..0..0..0..2....0..0..0..0....0..1..0..0....1..2..0..0....0..2..0..0

Crossrefs

Sequence in context: A156955 A196796 A196583 * A283625 A095752 A113267

Adjacent sequences: A197038 A197039 A197040 * A197042 A197043 A197044

Keyword

nonn

Author

R. H. Hardin Oct 08 2011

Status

approved