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A230464 Number of n X 3 0..2 arrays x(i,j) with each element horizontally, diagonally or antidiagonally next to at least one element with value (x(i,j)+1) mod 3, and upper left element zero. 1

%I

%S 0,0,114,1384,16926,212124,2647098,33046400,412565142,5150701380,

%T 64304187186,802809801448,10022730288270,125129422257516,

%U 1562186333636778,19503215967524816,243489156724526214

%N Number of n X 3 0..2 arrays x(i,j) with each element horizontally, diagonally or antidiagonally next to at least one element with value (x(i,j)+1) mod 3, and upper left element zero.

%C Column 3 of A230469.

%H R. H. Hardin, <a href="/A230464/b230464.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 12*a(n-1) +12*a(n-2) -66*a(n-3) -91*a(n-4) -186*a(n-5) +360*a(n-6) +216*a(n-7).

%F Empirical g.f.: 2*x^3*(57 + 8*x - 525*x^2 - 36*x^3 + 108*x^4) / (1 - 12*x - 12*x^2 + 66*x^3 + 91*x^4 + 186*x^5 - 360*x^6 - 216*x^7). - _Colin Barker_, Feb 09 2018

%e Some solutions for n=3:

%e ..0..2..0....0..2..0....0..0..0....0..2..0....0..1..2....0..1..1....0..1..1

%e ..1..1..2....2..1..1....1..1..2....2..1..1....0..0..0....2..2..1....1..2..2

%e ..0..0..0....0..0..2....0..2..1....0..0..0....1..2..2....1..0..2....1..0..1

%K nonn

%O 1,3

%A _R. H. Hardin_, Oct 20 2013

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Last modified August 19 03:31 EDT 2022. Contains 356216 sequences. (Running on oeis4.)