A207951 Number of 5Xn 0..1 arrays avoiding 0 0 1 and 0 1 1 horizontally and 0 1 0 and 1 0 1 vertically.

16, 256, 1232, 5929, 18172, 55696, 133812, 321489, 662256, 1364224, 2526384, 4678569, 8011752, 13719616, 22123992, 35676729, 54856032, 84345856, 124764640, 184552225, 264364100, 378691600, 527969260, 736091161, 1002761760, 1366041600

Offset: 1

Author

R. H. Hardin Feb 21 2012

Keywords

• nonn

Comments

Row 5 of A207949

Examples

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

Links

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

Formula

Empirical: a(n) = 2*a(n-1) +8*a(n-2) -18*a(n-3) -27*a(n-4) +72*a(n-5) +48*a(n-6) -168*a(n-7) -42*a(n-8) +252*a(n-9) -252*a(n-11) +42*a(n-12) +168*a(n-13) -48*a(n-14) -72*a(n-15) +27*a(n-16) +18*a(n-17) -8*a(n-18) -2*a(n-19) +a(n-20)