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A183996
Number of (n+1) X 3 0..2 arrays with all 2 X 2 subblock sums the same.
1
171, 309, 579, 1233, 2691, 6417, 15555, 40041, 104211, 282609, 771699, 2167353, 6111171, 17563617, 50584035, 147570921, 430968051, 1269505809, 3741492819, 11090690073, 32883337251, 97873303617, 291340216515, 869463485001
OFFSET
1,1
COMMENTS
Column 2 of A184003.
LINKS
FORMULA
Empirical: a(n) = 6*a(n-1) - 60*a(n-3) + 85*a(n-4) + 150*a(n-5) - 360*a(n-6) + 396*a(n-8) - 216*a(n-9).
Empirical g.f.: 3*x*(57 - 239*x - 425*x^2 + 2673*x^3 - 234*x^4 - 8968*x^5 + 5676*x^6 + 9252*x^7 - 7992*x^8) / ((1 - x)*(1 - 2*x)*(1 - 3*x)*(1 - 2*x^2)*(1 - 3*x^2)*(1 - 6*x^2)). - Colin Barker, Apr 09 2018
EXAMPLE
Some solutions for 4 X 3:
..1..2..1....0..2..0....2..0..2....0..2..0....1..2..2....0..2..1....2..0..1
..0..1..0....1..0..1....2..1..2....0..2..0....1..2..0....1..2..0....1..2..2
..1..2..1....1..1..1....1..1..1....0..2..0....1..2..2....1..1..2....2..0..1
..1..0..1....1..0..1....1..2..1....0..2..0....1..2..0....2..1..1....1..2..2
CROSSREFS
Cf. A184003.
Sequence in context: A349097 A120819 A115078 * A062907 A266315 A116459
KEYWORD
nonn
AUTHOR
R. H. Hardin, Jan 08 2011
STATUS
approved