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A232370 Number of n X 2 0..3 arrays with every 0 next to a 1, every 1 next to a 2 and every 2 next to a 3 horizontally, diagonally or antidiagonally, and no adjacent values equal. 1
2, 14, 58, 230, 934, 3794, 15354, 62266, 252346, 1022806, 4145638, 16802922, 68105158, 276041834, 1118844570, 4534868126, 18380594246, 74499685134, 301959937342, 1223895154962, 4960655920226, 20106384977054, 81494609451994 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

R. H. Hardin, Table of n, a(n) for n = 1..210

FORMULA

Empirical: a(n) = 2*a(n-1) + 7*a(n-2) + 6*a(n-3) - 2*a(n-4) - 3*a(n-5) + 2*a(n-6) + a(n-7).

Empirical g.f.: 2*x*(1 + 5*x + 8*x^2 + 2*x^3 - 6*x^4 + x^5 + x^6) / ((1 + x)*(1 - 3*x - 4*x^2 - 2*x^3 + 4*x^4 - x^5 - x^6)). - Colin Barker, Oct 05 2018

EXAMPLE

Some solutions for n=7:

..2..1....0..3....3..2....3..0....3..0....2..3....3..0....1..0....3..2....3..1

..0..3....2..1....1..2....1..2....1..0....0..1....1..0....1..2....1..0....2..1

..0..3....0..1....1..0....3..2....3..2....0..3....1..2....3..2....1..2....2..3

..2..1....2..1....3..0....1..2....1..2....2..3....3..0....3..2....3..2....2..3

..3..1....2..3....2..1....0..3....0..3....0..1....3..2....1..2....3..1....0..1

..0..2....2..1....2..3....0..1....2..1....3..2....1..0....3..0....2..1....0..1

..3..2....0..1....2..3....2..3....3..1....3..2....3..0....1..2....0..3....2..3

CROSSREFS

Column 2 of A232376.

Sequence in context: A096367 A232601 A285153 * A174704 A058738 A095376

Adjacent sequences:  A232367 A232368 A232369 * A232371 A232372 A232373

KEYWORD

nonn

AUTHOR

R. H. Hardin, Nov 23 2013

STATUS

approved

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Last modified August 9 01:35 EDT 2020. Contains 336310 sequences. (Running on oeis4.)