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A196450 Number of n X 2 0..4 arrays with each element x equal to the number its horizontal and vertical neighbors equal to 3,0,2,4,1 for x=0,1,2,3,4. 1
3, 6, 14, 30, 67, 146, 320, 706, 1550, 3403, 7481, 16443, 36131, 79399, 174500, 383499, 842796, 1852205, 4070612, 8945988, 19660603, 43208249, 94959144, 208692464, 458645240, 1007969053, 2215223460, 4868418432, 10699372182, 23514119454 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Every 0 is next to 0 3's, every 1 is next to 1 0's, every 2 is next to 2 2's, every 3 is next to 3 4's, every 4 is next to 4 1's.

Column 2 of A196456.

LINKS

R. H. Hardin, Table of n, a(n) for n = 1..200

FORMULA

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

Empirical g.f.: x*(3 + 2*x^2 - 7*x^3 - 5*x^4 - 9*x^5 - x^6) / (1 - 2*x - 3*x^3 + 2*x^4 + 3*x^5 + 5*x^6 + x^7). - Colin Barker, May 09 2018

EXAMPLE

Some solutions for n=4:

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

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

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

..1..0....0..1....0..1....1..1....0..0....0..1....0..1....1..0....1..1....1..1

CROSSREFS

Cf. A196456.

Sequence in context: A308580 A192672 A175656 * A131244 A077926 A091601

Adjacent sequences:  A196447 A196448 A196449 * A196451 A196452 A196453

KEYWORD

nonn

AUTHOR

R. H. Hardin, Oct 02 2011

STATUS

approved

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Last modified September 25 06:05 EDT 2020. Contains 337335 sequences. (Running on oeis4.)