A208348 Number of nX3 0..3 arrays with new values 0..3 introduced in row major order and no element equal to any knight-move neighbor (colorings ignoring permutations of colors).

5, 100, 1095, 12625, 153237, 1901508, 23658861, 294608660, 3672171940, 45806539501, 571496743787, 7130666296577, 88976864630029, 1110304369879641, 13855224093424061, 172897096309149243, 2157565319312754303

Offset: 1

Author

R. H. Hardin Feb 25 2012

Keywords

• nonn

Comments

Column 3 of A208353

Examples

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

Links

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

Formula

Empirical: a(n) = 21*a(n-1) -90*a(n-2) -532*a(n-3) +5973*a(n-4) -31315*a(n-5) +73172*a(n-6) +692866*a(n-7) -5872588*a(n-8) [phone]*a(n-9) [phone]*a(n-10) -238643374*a(n-11) [phone]*a(n-12) -1941550084*a(n-13) -2024947104*a(n-14) [phone]*a(n-15) -33786142200*a(n-16) [phone]*a(n-17) [phone]*a(n-18) -107335908376*a(n-19) [phone]*a(n-20) -118619608528*a(n-21) -73538891712*a(n-22) [phone]*a(n-23) -223952516832*a(n-24) [phone]*a(n-25) -245567709568*a(n-26) -217360125376*a(n-27) [phone]*a(n-28) -172433924352*a(n-29) -145159584768*a(n-30) [phone]*a(n-31) [phone]*a(n-32) -108640727040*a(n-33) -53571584000*a(n-34) [phone]*a(n-35) -18063360000*a(n-36) for n>39