A208429 Number of nX3 0..2 arrays with new values 0..2 introduced in row major order and no element equal to any knight-move neighbor (colorings ignoring permutations of colors).

5, 54, 129, 339, 1123, 4155, 15273, 55715, 205199, 758647, 2804053, 10360467, 38311103, 141717367, 524247989, 1939302323, 7174276855, 26541315667, 98190495765, 363259275051, 1343896481903, 4971825005443, 18393576694105

Offset: 1

Author

R. H. Hardin Feb 26 2012

Keywords

• nonn

Comments

Column 3 of A208434

Examples

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

Links

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

Formula

Empirical: a(n) = 3*a(n-1) +8*a(n-2) -18*a(n-3) -17*a(n-5) -116*a(n-6) +256*a(n-7) +184*a(n-8) -335*a(n-9) +260*a(n-10) -644*a(n-11) -368*a(n-12) +2013*a(n-13) -564*a(n-14) -1664*a(n-15) -1063*a(n-16) +1284*a(n-17) +3156*a(n-18) -1962*a(n-19) -256*a(n-20) +1020*a(n-21) -1448*a(n-22) -96*a(n-23) +144*a(n-24) +352*a(n-25) -128*a(n-26) for n>28