A222375 Number of nX4 0..3 arrays with no more than floor(nX4/2) elements unequal to at least one horizontal or vertical neighbor, with new values introduced in row major 0..3 order.

4, 18, 118, 1391, 20340, 342953, 6221698, 113556454, 2103238076, 38940850866, 724814585064, 13496985711211, 251700828899740, 4703187944642436, 87873606070564444, 1646203673458642042, 30815057060615530576

Offset: 1

Author

R. H. Hardin Feb 17 2013

Keywords

• nonn

Comments

Column 4 of A222378

Examples

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

Links

• R. H. Hardin, Table of n, a(n) for n = 1..50