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 A230670 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 2-x(i,j). 1

%I

%S 3,87,1173,17271,251595,3669765,53519163,780527655,11383251453,

%T 166013909415,2421155095347,35310246222069,514966385300499,

%U 7510295349852327,109530520538219973,1597398553655896551

%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 2-x(i,j).

%C Column 3 of A230675.

%H R. H. Hardin, <a href="/A230670/b230670.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 14*a(n-1) +9*a(n-2) -9*a(n-3) +30*a(n-4) -19*a(n-5).

%F Empirical g.f.: 3*x*(1 + 15*x - 24*x^2 + 31*x^3 - 21*x^4) / (1 - 14*x - 9*x^2 + 9*x^3 - 30*x^4 + 19*x^5). - _Colin Barker_, Feb 09 2018

%e Some solutions for n=3:

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

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

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

%K nonn

%O 1,1

%A _R. H. Hardin_, Oct 27 2013

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Last modified January 21 18:19 EST 2022. Contains 350479 sequences. (Running on oeis4.)