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A190030 Number of (n+2) X 8 binary arrays with every 3 X 3 subblock commuting with each horizontal and vertical neighbor 3 X 3 subblock. 1
880, 295, 430, 670, 970, 1230, 1494, 1834, 2338, 3142, 4226, 5674, 7686, 10543, 14268, 19361, 26383, 35721, 48439, 65943, 89488, 121506, 165332, 224537, 304933, 414641, 563273, 765114, 1040093, 1413201, 1919914, 2609473, 3545793, 4817559, 6547150 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
COMMENTS
Column 6 of A190033.
LINKS
FORMULA
Empirical: a(n) = 2*a(n-1) -a(n-2) +a(n-3) -2*a(n-4) +a(n-5) +a(n-6) -a(n-7) for n>14.
Empirical g.f.: x*(880 - 1465*x + 720*x^2 - 775*x^3 + 1525*x^4 - 760*x^5 - 981*x^6 + 601*x^7 + 69*x^8 + 56*x^9 - 96*x^10 - 60*x^11 + 225*x^13) / ((1 - x)*(1 - x - x^3 + x^4 - x^6)). - Colin Barker, May 03 2018
EXAMPLE
Some solutions for 4 X 8:
..1..0..0..0..0..0..0..1....0..0..0..0..0..0..0..1....0..0..0..0..0..0..1..0
..1..0..0..0..0..0..0..1....0..0..0..0..0..0..0..1....0..0..0..0..0..0..0..0
..1..0..0..0..0..0..0..1....1..0..0..0..0..0..0..1....0..0..0..0..0..0..0..0
..1..0..0..0..0..0..0..1....1..1..0..0..0..0..0..1....0..1..0..0..0..0..0..0
CROSSREFS
Cf. A190033.
Sequence in context: A252437 A129313 A063051 * A118799 A050424 A206341
KEYWORD
nonn
AUTHOR
R. H. Hardin, May 04 2011
STATUS
approved

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Last modified February 26 07:39 EST 2024. Contains 370335 sequences. (Running on oeis4.)