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A208290
Number of 6 X n 0..1 arrays avoiding 0 0 0 and 0 0 1 horizontally and 0 0 1 and 1 1 0 vertically.
1
12, 144, 636, 3900, 21096, 119580, 665892, 3733080, 20874900, 116842500, 653759952, 3658440924, 20471559852, 114555114720, 641024680212, 3587040344820, 20072307438840, 112320368080068, 628520819264292
OFFSET
1,1
COMMENTS
Row 6 of A208287.
LINKS
FORMULA
Empirical: a(n) = 4*a(n-1) + 11*a(n-2) - 10*a(n-3) - 10*a(n-4) + 6*a(n-5) + 2*a(n-6) - a(n-7).
Empirical g.f.: 12*x*(1 - x)*(1 + 9*x + 3*x^2 - 6*x^3 - x^4 + x^5) / (1 - 4*x - 11*x^2 + 10*x^3 + 10*x^4 - 6*x^5 - 2*x^6 + x^7). - Colin Barker, Jun 30 2018
EXAMPLE
Some solutions for n=4:
..0..1..1..0....0..1..1..0....1..1..0..1....0..1..0..0....1..1..1..1
..0..1..0..1....0..1..1..0....1..1..0..0....1..0..1..1....0..1..1..1
..0..1..0..1....0..1..1..0....1..1..0..0....1..1..1..1....1..1..1..1
..0..1..0..1....0..1..1..0....1..1..0..0....1..0..1..1....1..1..1..1
..0..1..0..1....0..1..1..0....1..1..0..0....1..1..1..1....1..1..1..1
..0..1..0..1....0..1..1..0....1..1..0..0....1..0..1..1....1..1..1..1
CROSSREFS
Cf. A208287.
Sequence in context: A207406 A207707 A207252 * A208139 A208145 A206937
KEYWORD
nonn
AUTHOR
R. H. Hardin, Feb 25 2012
STATUS
approved