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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.
1
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
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
KEYWORD
nonn
AUTHOR
R. H. Hardin, Jan 23 2012
STATUS
approved