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A189258
Number of n X 3 binary arrays without the pattern 0 0 1 diagonally, antidiagonally or horizontally.
1
7, 49, 280, 1600, 8985, 50397, 282332, 1581428, 8857677, 49611209, 277868792, 1556321080, 8716833601, 48822302485, 273449899316, 1531571519964, 8578212427349, 48045897623297, 269101318957392, 1507215463960672
OFFSET
1,1
COMMENTS
Column 3 of A189264.
LINKS
FORMULA
Empirical: a(n) = 6*a(n-1) -2*a(n-2) +a(n-4) -50*a(n-5) -6*a(n-6) +140*a(n-7) -56*a(n-8).
Empirical g.f.: x*(7 + 7*x + 18*x^3 - 62*x^4 - 12*x^5 + 132*x^6 - 56*x^7) / (1 - 6*x + 2*x^2 - x^4 + 50*x^5 + 6*x^6 - 140*x^7 + 56*x^8). - Colin Barker, May 01 2018
EXAMPLE
Some solutions for 4 X 3:
..1..1..1....0..1..0....1..1..0....0..1..1....1..1..1....0..1..0....1..1..0
..0..0..0....1..1..0....0..0..0....0..1..1....1..0..1....0..1..0....1..1..1
..0..0..0....1..1..1....0..1..1....0..1..1....0..0..0....1..1..1....0..1..1
..0..1..0....0..1..0....1..0..0....1..1..1....1..0..0....1..1..1....1..0..1
CROSSREFS
Cf. A189264.
Sequence in context: A224131 A218266 A213295 * A188748 A188986 A146884
KEYWORD
nonn
AUTHOR
R. H. Hardin, Apr 19 2011
STATUS
approved