A197665 Number of n X n 0..4 arrays with each element x equal to the number of its horizontal and vertical neighbors equal to 4,0,1,0,1 for x=0,1,2,3,4.
1, 9, 95, 5005, 709083, 311676959, 417293944115, 1717065757366333
Offset: 1
Keywords
Examples
Some solutions for n=4 ..2..1..1..1....1..0..0..0....0..1..2..0....0..0..3..0....0..1..2..0 ..1..0..0..0....2..0..3..0....1..4..1..0....0..0..0..3....0..1..1..0 ..1..0..0..3....1..1..2..0....1..1..1..0....0..0..3..0....1..1..2..0 ..1..0..3..0....0..2..1..0....0..0..2..1....1..1..2..1....1..0..0..0
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