A198902 Number of nX4 0..4 arrays with values 0..4 introduced in row major order and no element equal to any horizontal or vertical neighbor.

5, 380, 50384, 6907736, 948656912, 130292546801, 17895005957823, 2457786852894234, 337564362706067534, 46362726246946052884, 6367681611531782236418, 874568266109492180669275

Offset: 1

Author

R. H. Hardin Oct 31 2011

Keywords

• nonn

Comments

Column 4 of A198906

Examples

			Some solutions with values 0 to 4 for n=5
..0..1..0..1....0..1..0..1....0..1..0..1....0..1..0..1....0..1..0..1
..1..0..1..0....1..0..1..0....1..0..1..0....1..0..1..0....1..0..1..0
..0..2..3..1....0..2..3..1....0..2..3..1....0..2..0..2....0..2..0..3
..1..0..4..0....2..3..0..4....1..0..2..0....3..1..2..1....3..0..3..4
..2..1..0..2....1..2..4..0....4..3..4..2....4..0..1..3....2..3..0..3
		

Links

• R. H. Hardin, Table of n, a(n) for n = 1..200

Formula

Empirical: a(n) = 163*a(n-1) -3751*a(n-2) +32097*a(n-3) -120287*a(n-4) +201471*a(n-5) -148296*a(n-6) +38604*a(n-7)