A208878 Number of 7Xn 0..3 arrays with new values 0..3 introduced in row major order and no element equal to more than one of its immediate leftward or upward or right-upward antidiagonal neighbors.

715, 5826959, 40380275500, 271499374919883, 1820216057105650386, 12201956787655438957014, 81798476241280856702695038, 548357000894509223687629476021, 3676054154412185019451007694406065

Offset: 1

Author

R. H. Hardin Mar 02 2012

Keywords

• nonn

Comments

Row 7 of A208872

Examples

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

Links

• R. H. Hardin, Table of n, a(n) for n = 1..18