A198718 Number of nX3 0..6 arrays with values 0..6 introduced in row major order and no element equal to any horizontal or vertical neighbor.

2, 34, 2027, 232841, 34003792, 5315840795, 846047363854, 135284283124811, 21658679381667910, 3468618095206638077, 555543217744635684040, 88979288917879960297469, 14251565534424509235823960

Offset: 1

Author

R. H. Hardin Oct 29 2011

Keywords

• nonn

Comments

Column 3 of A198723

Examples

			Some solutions with all values 0 to 6 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..0..4....3..0..3....3..4..3....3..2..0....3..4..5....2..3..4....3..4..5
..5..3..5....4..5..2....4..5..6....4..5..3....5..6..4....1..0..5....4..6..4
..2..6..2....2..0..6....5..1..5....1..6..0....0..5..1....6..2..4....3..4..6
		

Links

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

Formula

Empirical: a(n) = 234*a(n-1) -13497*a(n-2) +283640*a(n-3) -2626919*a(n-4) [phone]*a(n-5) -30282843*a(n-6) [phone]*a(n-7) -23115780*a(n-8) +4848336*a(n-9)