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

1,1

Comments

Column 2 of A203091

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)

Example

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

Crossrefs

Sequence in context: A002289 A158078 A157356 * A245790 A070193 A054737

Adjacent sequences: A203082 A203083 A203084 * A203086 A203087 A203088

Keyword

nonn

Author

R. H. Hardin Dec 29 2011

Status

approved