A205067 Number of (n+1)X4 0..1 arrays with the number of rightwards and downwards edge increases in each 2X2 subblock differing from the number in all its horizontal and vertical neighbors

98, 90, 144, 220, 347, 524, 850, 1268, 2048, 3060, 4942, 7388, 11938, 17836, 28826, 43060, 69621, 103956, 168108, 250972, 405913, 605900, 980086, 1462772, 2366374, 3531444, 5713346, 8525660, 13794016, 20582764, 33303134, 49691188, 80403523

Offset

1,1

Comments

Column 3 of A205072

Links

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

Formula

Empirical: a(n) = 3*a(n-2) -2*a(n-6) -2*a(n-8) -4*a(n-10) +2*a(n-14) +3*a(n-16) +a(n-18) for n>20

Example

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

Crossrefs

Sequence in context: A033418 A120310 A129887 * A307371 A273460 A095605

Adjacent sequences: A205064 A205065 A205066 * A205068 A205069 A205070

Keyword

nonn

Author

R. H. Hardin Jan 21 2012

Status

approved