A207560 Number of n X 4 0..1 arrays avoiding 0 0 1 and 0 1 0 horizontally and 0 1 1 and 1 1 0 vertically.

9, 81, 241, 636, 2135, 6709, 23276, 78733, 277781, 973608, 3477827, 12422849, 44780404, 161681185, 586480585, 2130883040, 7761845079, 28308582237, 103395253764, 377977638085, 1382951559309, 5062965194920, 18545296800603

Offset

1,1

Comments

Column 4 of A207564.

Links

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

Formula

Empirical: a(n) = 7*a(n-1) -2*a(n-2) -73*a(n-3) +95*a(n-4) +258*a(n-5) -429*a(n-6) -357*a(n-7) +730*a(n-8) +125*a(n-9) -499*a(n-10) +70*a(n-11) +106*a(n-12) -30*a(n-13) for n>14.

Example

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

Crossrefs

Sequence in context: A208556 A063824 A357450 * A207415 A207020 A207364

Adjacent sequences: A207557 A207558 A207559 * A207561 A207562 A207563

Keyword

nonn

Author

R. H. Hardin, Feb 18 2012

Status

approved