A208684 Number of nX4 0..1 arrays avoiding 0 0 0 and 0 0 1 horizontally and 0 1 1 and 1 0 1 vertically

10, 100, 282, 927, 3430, 11067, 34627, 111642, 356116, 1121500, 3542847, 11196360, 35283685, 111150345, 350234962, 1103073000, 3473204686, 10936009567, 34431544350, 108396961047, 341246282767, 1074267088938, 3381794658280

Offset

1,1

Comments

Column 4 of A208688

Links

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

Formula

Empirical: a(n) = 4*a(n-1) -3*a(n-2) +10*a(n-3) -27*a(n-4) -6*a(n-5) -15*a(n-6) +51*a(n-7) +41*a(n-8) +31*a(n-9) -51*a(n-10) -29*a(n-11) -27*a(n-12) +15*a(n-13) +6*a(n-14) +3*a(n-15) -4*a(n-16) +a(n-17) +a(n-19)

Example

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

Crossrefs

Sequence in context: A207173 A207456 A208836 * A207348 A207770 A207897

Adjacent sequences: A208681 A208682 A208683 * A208685 A208686 A208687

Keyword

nonn

Author

R. H. Hardin Mar 01 2012

Status

approved