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A208486
Number of (n+1) X 3 0..3 arrays with the number of clockwise edge increases in every 2 X 2 subblock equal to the number of counterclockwise edge increases.
1
1448, 33416, 773288, 17903016, 414522184, 9597910280, 222232271912, 5145622169576, 119143055140232, 2758668946684232, 63874930914742632, 1478976595260586280, 34244604867749825992, 792908397874578443656
OFFSET
1,1
COMMENTS
Column 2 of A208492.
LINKS
FORMULA
Empirical: a(n) = 32*a(n-1) - 227*a(n-2) + 528*a(n-3) - 328*a(n-4) - 104*a(n-5).
Empirical g.f.: 8*x*(181 - 1615*x + 4084*x^2 - 2664*x^3 - 832*x^4) / (1 - 32*x + 227*x^2 - 528*x^3 + 328*x^4 + 104*x^5). - Colin Barker, Jul 03 2018
EXAMPLE
Some solutions for n=4:
..1..1..1....1..3..2....0..0..1....2..0..3....3..0..1....0..0..3....1..1..3
..2..1..2....3..1..3....2..0..0....0..2..0....0..0..0....0..1..0....0..1..1
..3..2..1....2..3..1....3..1..1....3..1..2....2..0..1....2..0..2....0..1..0
..2..0..2....1..2..3....0..2..2....2..0..1....1..2..0....2..2..0....0..1..1
..1..3..0....0..1..2....1..3..2....0..1..0....1..1..2....3..2..2....3..0..0
CROSSREFS
Cf. A208492.
Sequence in context: A226097 A023311 A318710 * A242038 A045099 A325883
KEYWORD
nonn
AUTHOR
R. H. Hardin Feb 27 2012
STATUS
approved