A203085 Number of (n+2)X4 binary arrays avoiding patterns 000 and 101 in rows and columns.

253, 787, 2237, 6615, 19723, 57699, 169561, 500813, 1473813, 4336509, 12776787, 37624405, 110768047, 326202095, 960592477, 2828495527, 8329036847, 24526561909, 72221962493, 212669436487, 626242809531, 1844074518231

Offset: 1

Author

R. H. Hardin Dec 29 2011

Keywords

• nonn

Comments

Column 2 of A203091

Examples

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

Links

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

Formula

Empirical: a(n) = a(n-1) +2*a(n-2) +10*a(n-3) +6*a(n-4) -5*a(n-5) -10*a(n-6) -8*a(n-7) +2*a(n-8) +10*a(n-9) -24*a(n-10) -20*a(n-11) +23*a(n-12) +22*a(n-13) -10*a(n-14)