A208048 Number of nX6 0..3 arrays with new values 0..3 introduced in row major order and no element equal to any horizontal, vertical or antidiagonal neighbor (colorings ignoring permutations of colors).

41, 512, 7540, 118096, 1897888, 30818432, 502504448, 8206614784, 134107752704, 2192020679040, 35832132655104, 585752326535168, 9575474013944320, 156533905282970624, 2558923378953086464, 41831786939400151040

Offset: 1

Author

R. H. Hardin Feb 22 2012

Keywords

• nonn

Comments

Column 6 of A208050

Examples

			Some solutions for n=4
..0..1..2..0..2..3....0..1..2..0..1..3....0..1..2..1..3..0....0..1..2..3..0..1
..3..0..1..3..0..2....2..0..1..2..0..1....3..0..3..2..1..3....3..0..1..2..3..2
..1..2..0..2..3..0....3..2..3..1..2..3....1..2..1..3..0..2....1..2..0..1..0..3
..3..1..3..0..1..2....1..0..2..3..0..1....3..0..2..1..3..1....3..1..2..3..1..0
		

Links

• R. H. Hardin, Table of n, a(n) for n = 1..210

Formula

Empirical: a(n) = 40*a(n-1) -672*a(n-2) +7048*a(n-3) -53920*a(n-4) +315080*a(n-5) -1388592*a(n-6) +4290880*a(n-7) -7204704*a(n-8) -5415680*a(n-9) [phone]*a(n-10) -131003904*a(n-11) -9639424*a(n-12) [phone]*a(n-13) -1570279424*a(n-14) [phone]*a(n-15) -11382816768*a(n-16) [phone]*a(n-17) -31692161024*a(n-18) [phone]*a(n-19) -34628173824*a(n-20) [phone]*a(n-21) for n>22