A198977 Number of nX3 0..5 arrays with values 0..5 introduced in row major order and no element equal to any horizontal or vertical neighbor.

2, 34, 1835, 146286, 12662226, 1112962873, 98102456246, 8651794282083, 763087851014929, 67305520316532514, 5936469991284318525, 523607833526831199696, 46183202315902474606576, 4073445973766659727007243

Offset: 1

Author

R. H. Hardin Nov 01 2011

Keywords

• nonn

Comments

Column 3 of A198982

Examples

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

Links

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

Formula

Empirical: a(n) = 116*a(n-1) -2685*a(n-2) +21394*a(n-3) -74475*a(n-4) +117904*a(n-5) -80343*a(n-6) +18090*a(n-7)