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A186583
Number of (n+3) X 6 0..2 arrays with every 4 X 4 subblock commuting with each horizontal and vertical neighbor 4 X 4 subblock.
1
38608, 1991, 5879, 39757, 115699, 149305, 156259, 160945, 165739, 171145, 185131, 230017, 470139, 778697, 1118323, 1529121, 2339979, 3298521, 4347171, 5627937, 8189067, 11662681, 15995763, 21614673, 31416027, 44959433, 62319075, 84811905
OFFSET
1,1
COMMENTS
Column 3 of A186589.
LINKS
FORMULA
Empirical: a(n) = 2*a(n-1) - a(n-2) + 2*a(n-4) - 4*a(n-5) + 2*a(n-6) + 2*a(n-8) - 2*a(n-9) for n>13
Empirical g.f.: x*(38608 - 75225*x + 40505*x^2 + 29990*x^3 - 35152*x^4 + 108114*x^5 - 107662*x^6 - 62248*x^7 - 161236*x^8 + 158518*x^9 + 54108*x^10 - 32320*x^11 + 43136*x^12) / ((1 - x)*(1 - x - 2*x^4 + 2*x^5 - 2*x^8)). - Colin Barker, Apr 18 2018
EXAMPLE
Some solutions for 5 X 6:
..0..0..0..0..0..0....1..1..1..1..1..1....0..0..0..2..0..2....1..0..0..0..0..0
..0..0..0..0..0..0....0..2..0..2..0..2....0..0..0..0..0..0....0..0..0..0..0..0
..0..0..0..0..0..0....1..1..1..1..1..1....0..0..0..0..0..0....0..0..0..0..0..0
..2..0..0..0..0..0....2..0..2..0..2..0....0..0..0..0..0..0....0..0..0..0..0..0
..0..2..0..0..0..0....1..1..1..1..1..1....0..0..0..0..0..0....0..1..0..0..0..0
CROSSREFS
Cf. A186589.
Sequence in context: A321494 A252103 A074484 * A043666 A180462 A185851
KEYWORD
nonn
AUTHOR
R. H. Hardin, Feb 24 2011
STATUS
approved