A222881 Number of 4Xn 0..3 arrays with no more than floor(4Xn/2) elements equal to at least one horizontal or antidiagonal neighbor, with new values introduced in row major 0..3 order.

15, 2150, 443510, 95867967, 20978414941, 4643150795564, 1036481888251762, 232912437941917635, 52614561200004212957, 11936312777288007185980, 2717468404561524996790251, 620503805193057253513443782

Offset: 1

Author

R. H. Hardin Mar 08 2013

Keywords

• nonn

Comments

Row 4 of A222878

Examples

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

Links

• R. H. Hardin, Table of n, a(n) for n = 1..16