A205187 Number of (n+1)X2 0..1 arrays with the number of clockwise edge increases in every 2X2 subblock differing from each horizontal or vertical neighbor

16, 24, 48, 72, 144, 216, 432, 648, 1296, 1944, 3888, 5832, 11664, 17496, 34992, 52488, 104976, 157464, 314928, 472392, 944784, 1417176, 2834352, 4251528, 8503056, 12754584, 25509168, 38263752, 76527504, 114791256, 229582512, 344373768

Offset

1,1

Comments

Column 1 of A205193

Links

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

Formula

Empirical: a(n) = 3*a(n-2)

Example

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

Crossrefs

Sequence in context: A045875 A046434 A111046 * A162819 A029720 A204696

Adjacent sequences: A205184 A205185 A205186 * A205188 A205189 A205190

Keyword

nonn

Author

R. H. Hardin Jan 23 2012

Status

approved