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A230782 Number of n X 2 0..3 arrays x(i,j) with each element horizontally, vertically, diagonally or antidiagonally next to at least one element with value (x(i,j)+1) mod 4, and upper left element zero. 1
0, 6, 86, 820, 8154, 82576, 833986, 8417644, 84971714, 857764344, 8658840234, 87407976260, 882353220314, 8907050256960, 89913587800402, 907646529844380, 9162377384021426, 92491026597941000, 933664882212237754 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

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

FORMULA

Empirical: a(n) = 10*a(n-1) - 3*a(n-2) + 44*a(n-3) - 40*a(n-4) + 8*a(n-5) - 192*a(n-6).

Empirical g.f.: 2*x^2*(3 + 13*x - 11*x^2 - 26*x^3 - 24*x^4) / (1 - 10*x + 3*x^2 - 44*x^3 + 40*x^4 - 8*x^5 + 192*x^6). - Colin Barker, Sep 22 2018

EXAMPLE

Some solutions for n=3:

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

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

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

CROSSREFS

Column 2 of A230787.

Sequence in context: A187740 A332407 A209035 * A318042 A155654 A231165

Adjacent sequences:  A230779 A230780 A230781 * A230783 A230784 A230785

KEYWORD

nonn

AUTHOR

R. H. Hardin, Oct 30 2013

STATUS

approved

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Last modified October 25 11:00 EDT 2021. Contains 348239 sequences. (Running on oeis4.)