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A208066 Number of n X 5 0..1 arrays avoiding 0 0 0 and 1 1 1 horizontally and 0 0 1 and 0 1 1 vertically. 1
16, 256, 704, 1936, 3696, 7056, 11424, 18496, 27200, 40000, 55200, 76176, 100464, 132496, 168896, 215296, 267264, 331776, 403200, 490000, 585200, 698896, 822624, 968256, 1125696, 1308736, 1505504, 1731856, 1974000, 2250000, 2544000, 2876416 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
COMMENTS
Column 5 of A208069.
LINKS
FORMULA
Empirical: a(n) = 2*a(n-1) + 2*a(n-2) - 6*a(n-3) + 6*a(n-5) - 2*a(n-6) - 2*a(n-7) + a(n-8) for n>9.
Empirical g.f.: 16*x*(1 + 14*x + 10*x^2 + 7*x^3 - 3*x^4 - 5*x^5 + 2*x^6 + 2*x^7 - x^8) / ((1 - x)^5*(1 + x)^3). - Colin Barker, Jun 27 2018
EXAMPLE
Some solutions for n=4.
..1..0..1..1..0....1..1..0..0..1....1..1..0..1..1....0..0..1..0..0
..0..0..1..0..1....1..0..1..1..0....0..0..1..0..1....1..1..0..0..1
..0..0..1..0..0....1..1..0..0..1....0..1..0..1..0....0..0..1..0..0
..0..0..1..0..1....0..0..1..1..0....0..0..1..0..1....0..1..0..0..1
CROSSREFS
Cf. A208069.
Sequence in context: A207842 A135554 A208376 * A207931 A207848 A208837
KEYWORD
nonn
AUTHOR
R. H. Hardin, Feb 23 2012
STATUS
approved

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Last modified July 17 17:29 EDT 2024. Contains 374377 sequences. (Running on oeis4.)