A198713 Number of nX6 0..3 arrays with values 0..3 introduced in row major order and no element equal to any horizontal or vertical neighbor.

41, 8404, 1749965, 364637102, 75987485516, 15835552812749, 3300094936852775, 687733321797971342, 143322307142433346196, 29868095632655586533219, 6224454258216624967544685, 1297164418016611898106044912

Offset: 1

Author

R. H. Hardin Oct 29 2011

Keywords

• nonn

Comments

Column 6 of A198715

Examples

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

Links

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

Formula

Empirical: a(n) = 313*a(n-1) -25836*a(n-2) +915863*a(n-3) -16213670*a(n-4) [phone]*a(n-5) -517271096*a(n-6) -1142631169*a(n-7) [phone]*a(n-8) -49834494904*a(n-9) [phone]*a(n-10) [phone]*a(n-11) -186980689770*a(n-12) [phone]*a(n-13) -21008679048*a(n-14)