A205192 Number of (n+1) X 8 0..1 arrays with the number of clockwise edge increases in every 2 X 2 subblock differing from each horizontal or vertical neighbor.

432, 440, 708, 864, 1568, 2048, 3904, 4608, 7872, 9216, 15808, 18944, 32960, 39936, 69824, 84480, 147520, 178176, 310848, 375296, 654656, 790528, 1379136, 1665536, 2905792, 3509248, 6122432, 7393792, 12899520, 15578112, 27178176, 32821760

Offset

1,1

Comments

Column 7 of A205193.

Links

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

Formula

Empirical: a(n) = 2*a(n-2) +a(n-8) for n>13.

Empirical g.f.: 4*x*(108 + 110*x - 39*x^2 - 4*x^3 + 38*x^4 + 80*x^5 + 192*x^6 + 128*x^7 - 92*x^8 - 110*x^9 - 161*x^10 - 88*x^11 - 56*x^12) / (1 - 2*x^2 - x^8). - Colin Barker, Jun 11 2018

Example

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

Crossrefs

Cf. A205193.

Sequence in context: A301645 A063463 A175026 * A066419 A245469 A069781

Adjacent sequences: A205189 A205190 A205191 * A205193 A205194 A205195

Keyword

nonn

Author

R. H. Hardin, Jan 23 2012

Status

approved