A228688 Number of 7Xn binary arrays with no two ones adjacent horizontally, diagonally or antidiagonally.

128, 577, 21305, 176032, 4008817, 44171841, 806190208, 10258304689, 168184756793, 2301665823616, 35784406285057, 508094306671233, 7692715116119040, 111277331056067617, 1662525457133097145

Offset: 1

Author

R. H. Hardin Aug 30 2013

Keywords

• nonn

Comments

Row 7 of A228683

Examples

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

Links

• R. H. Hardin, Table of n, a(n) for n = 1..210

Formula

Empirical: a(n) = 9*a(n-1) +184*a(n-2) -1201*a(n-3) -7155*a(n-4) +46048*a(n-5) +70745*a(n-6) -591673*a(n-7) -154744*a(n-8) +3207657*a(n-9) -715173*a(n-10) -7580648*a(n-11) +3369552*a(n-12) +7114920*a(n-13) -3800952*a(n-14) -1923264*a(n-15) +1083456*a(n-16)