A206311 Number of (n+1)X2 0..3 arrays with the number of clockwise edge increases in every 2X2 subblock equal to two, and every 2X2 determinant nonzero

112, 873, 6831, 53463, 418468, 3275406, 25637095, 200665376, 1570637751, 12293615779, 96223962193, 753159288558, 5895089964664, 46141747460483, 361158332020412, 2826840073596765, 22126098426129671, 173184268942327111

Offset

1,1

Comments

Column 1 of A206318

Links

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

Formula

Empirical: a(n) = 5*a(n-1) +21*a(n-2) +13*a(n-3) -31*a(n-4) -17*a(n-5) +34*a(n-6) +2*a(n-7) -9*a(n-8) -a(n-9)

Example

Some solutions for n=4
..2..2....3..0....0..1....3..2....1..1....0..1....3..1....2..0....1..0....2..2
..0..3....2..2....1..3....0..3....3..2....1..2....3..2....1..1....0..1....0..3
..3..0....0..3....2..1....3..0....0..3....0..2....1..3....3..2....1..2....2..1
..0..1....1..0....1..0....1..3....2..0....2..1....3..0....2..1....2..1....1..0
..2..3....2..1....3..1....2..1....0..1....0..3....1..1....3..2....0..2....2..1

Crossrefs

Sequence in context: A203789 A211448 A206318 * A343372 A330418 A235311

Adjacent sequences: A206308 A206309 A206310 * A206312 A206313 A206314

Keyword

nonn

Author

R. H. Hardin Feb 06 2012

Status

approved