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A188556 Number of 5 X n binary arrays without the pattern 0 1 diagonally, vertically, antidiagonally or horizontally. 2
6, 11, 20, 36, 64, 112, 192, 321, 522, 825, 1268, 1898, 2772, 3958, 5536, 7599, 10254, 13623, 17844, 23072, 29480, 37260, 46624, 57805, 71058, 86661, 104916, 126150, 150716, 178994, 211392, 248347, 290326, 337827, 391380, 451548, 518928, 594152 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
COMMENTS
Row 5 of A188553.
LINKS
FORMULA
Empirical: a(n) = (1/120)*n^5 - (1/24)*n^4 + (3/8)*n^3 + (1/24)*n^2 + (157/60)*n + 3.
Conjectures from Colin Barker, Apr 27 2018: (Start)
G.f.: x*(6 - 25*x + 44*x^2 - 39*x^3 + 18*x^4 - 3*x^5) / (1 - x)^6.
a(n) = 6*a(n-1) - 15*a(n-2) + 20*a(n-3) - 15*a(n-4) + 6*a(n-5) - a(n-6) for n>6.
(End)
EXAMPLE
Some solutions for 5 X 3:
..1..1..0....1..1..1....1..1..1....0..0..0....1..1..1....1..1..1....1..1..1
..0..0..0....1..1..1....0..0..0....0..0..0....1..1..0....1..1..1....1..1..1
..0..0..0....1..1..1....0..0..0....0..0..0....1..0..0....1..1..1....1..1..1
..0..0..0....1..1..0....0..0..0....0..0..0....0..0..0....1..1..0....1..1..1
..0..0..0....1..0..0....0..0..0....0..0..0....0..0..0....0..0..0....0..0..0
CROSSREFS
Cf. A188553.
Sequence in context: A160842 A365351 A007745 * A021011 A000382 A208670
KEYWORD
nonn
AUTHOR
R. H. Hardin, Apr 04 2011
STATUS
approved

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Last modified May 17 23:39 EDT 2024. Contains 372608 sequences. (Running on oeis4.)