A208143 Number of 4Xn 0..1 arrays avoiding 0 0 1 and 0 1 1 horizontally and 0 0 1 and 1 0 1 vertically.

8, 64, 240, 900, 2400, 6400, 14000, 30625, 58800, 112896, 197568, 345744, 564480, 921600, 1425600, 2205225, 3267000, 4840000, 6921200, 9897316, 13741728, 19079424, 25836720, 34987225, 46373600, 61465600, 79968000, 104040000

Offset: 1

Author

R. H. Hardin Feb 23 2012

Keywords

• nonn

Comments

Row 4 of A208142

Examples

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

Links

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

Formula

Empirical: a(n) = 2*a(n-1) +6*a(n-2) -14*a(n-3) -14*a(n-4) +42*a(n-5) +14*a(n-6) -70*a(n-7) +70*a(n-9) -14*a(n-10) -42*a(n-11) +14*a(n-12) +14*a(n-13) -6*a(n-14) -2*a(n-15) +a(n-16)