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A253360
Number of (n+2) X (1+2) 0..1 arrays with every 2 X 2 and 3 X 3 subblock diagonal maximum minus antidiagonal minimum unequal to its neighbors horizontally and vertically.
1
152, 272, 560, 976, 1904, 3472, 6544, 12048, 22704, 41680, 78800, 144464, 273264, 501008, 947472, 1737360, 3285296, 6024272, 11391824, 20889040, 39501296, 72432784, 136970896, 251161104, 474946992, 870902224, 1646880464, 3019856720
OFFSET
1,1
LINKS
FORMULA
Empirical: a(n) = 4*a(n-2) - 3*a(n-4) + 4*a(n-6).
Empirical g.f.: 8*x*(19 + 34*x - 6*x^2 - 14*x^3 + 15*x^4 + 48*x^5) / (1 - 4*x^2 + 3*x^4 - 4*x^6). - Colin Barker, Dec 11 2018
EXAMPLE
Some solutions for n=4:
..1..1..1....0..0..1....0..1..1....0..1..1....0..1..1....0..0..0....1..0..1
..1..0..1....1..1..1....0..0..0....1..0..0....0..1..0....1..0..1....1..1..0
..0..1..0....1..0..1....0..1..0....0..0..0....1..1..1....0..1..0....1..0..1
..1..1..1....0..1..1....0..0..0....1..0..1....0..1..1....0..0..0....0..1..1
..0..1..1....1..0..1....0..1..0....0..0..0....1..0..1....0..1..0....1..0..1
..1..0..1....0..1..1....1..0..1....1..0..1....0..1..1....0..0..1....1..1..1
CROSSREFS
Column 1 of A253367.
Sequence in context: A185394 A097640 A253367 * A252363 A248816 A038857
KEYWORD
nonn
AUTHOR
R. H. Hardin, Dec 30 2014
STATUS
approved