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A196479 Number of n X 2 0..4 arrays with each element x equal to the number its horizontal and vertical neighbors equal to 3,0,2,1,4 for x=0,1,2,3,4. 2
3, 6, 14, 36, 83, 192, 468, 1112, 2624, 6267, 14941, 35493, 84487, 201229, 478826, 1139543, 2712764, 6456865, 15367802, 36579318, 87067091, 207234557, 493260338, 1174064036, 2794503372, 6651474771, 15831865426, 37683024434, 89693152856 (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 1's, every 4 is next to 4 4's.

Column 2 of A196485.

LINKS

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

FORMULA

Empirical: a(n) = 2*a(n-1) + 4*a(n-3) - 3*a(n-4) - 3*a(n-5) - a(n-6) + a(n-7) -a(n-8).

Empirical g.f.: x*(3 + 2*x^2 - 4*x^3 - 4*x^4 - 3*x^5 + 3*x^6 - 3*x^7) / (1 - 2*x - 4*x^3 + 3*x^4 + 3*x^5 + x^6 - x^7 + x^8). - Colin Barker, Mar 01 2018

EXAMPLE

Some solutions for n=4:

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

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

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

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

CROSSREFS

Cf. A196485.

Sequence in context: A018017 A184785 A332362 * A147772 A129703 A001550

Adjacent sequences:  A196476 A196477 A196478 * A196480 A196481 A196482

KEYWORD

nonn

AUTHOR

R. H. Hardin, Oct 03 2011

STATUS

approved

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Last modified November 26 21:07 EST 2021. Contains 349344 sequences. (Running on oeis4.)