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A190031 Number of (n+2) X 9 binary arrays with every 3 X 3 subblock commuting with each horizontal and vertical neighbor 3 X 3 subblock. 1
1205, 355, 506, 790, 1162, 1494, 1910, 2362, 3002, 4006, 5390, 7234, 9790, 13178, 17955, 24448, 33157, 45099, 61313, 83131, 112959, 153552, 208458, 283316, 385153, 523121, 710869, 966189, 1312546, 1783541, 2423945, 3293354, 4475149, 6081673 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
COMMENTS
Column 7 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>15.
Empirical g.f.: x*(1205 - 2055*x + 1001*x^2 - 1072*x^3 + 2143*x^4 - 1041*x^5 - 1254*x^6 + 798*x^7 + 77*x^8 - 4*x^9 - 28*x^10 - 60*x^11 - 68*x^12 + 289*x^14) / ((1 - x)*(1 - x - x^3 + x^4 - x^6)). - Colin Barker, May 03 2018
EXAMPLE
Some solutions for 4 X 9:
..0..0..0..0..0..0..0..1..0....0..0..0..0..0..0..0..0..1
..0..0..0..0..0..0..0..0..0....0..0..0..0..0..0..0..0..0
..0..0..0..0..0..0..0..0..0....0..0..0..0..0..0..0..0..0
..1..0..0..0..0..0..0..0..0....1..0..0..0..0..0..0..0..0
CROSSREFS
Cf. A190033.
Sequence in context: A230838 A210015 A259521 * A254694 A279983 A187862
KEYWORD
nonn
AUTHOR
R. H. Hardin, May 04 2011
STATUS
approved

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Last modified April 21 06:29 EDT 2024. Contains 371850 sequences. (Running on oeis4.)