A233201 Number of nX7 0..7 arrays with no element x(i,j) adjacent to itself or value 7-x(i,j) horizontally, antidiagonally or vertically, top left element zero, and 1 appearing before 2 3 4 5 and 6, 2 appearing before 3 4 and 5, and 3 appearing before 4 in row major order (unlabelled 8-colorings with no clashing color pairs).

1248, 2098176, 5496242176, 15635845218304, 46111939268444160, 138127371171167993856, 416547612309880393695232, 1259808519497450508966166528, 3814894993577338604838516162560

Offset: 1

Author

R. H. Hardin, Dec 05 2013

Keywords

• nonn

Comments

Column 7 of A233202

Examples

			Some solutions for n=2
..0..1..0..2..6..5..0....0..1..0..2..6..3..7....0..1..0..2..7..3..2
..3..2..6..3..7..1..3....3..2..6..3..5..1..4....2..4..6..4..2..6..4
		

Links

• R. H. Hardin, Table of n, a(n) for n = 1..101