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A232018 Number of n X 3 0..2 arrays with no element less than a strict majority of its horizontal and antidiagonal neighbors.

%I A232018 #7 Oct 01 2018 21:10:18
%S A232018 9,66,852,11517,156913,2125749,28852936,391447970,5311170384,
%T A232018 72061691152,977727048997,13265735926493,179988561188366,
%U A232018 2442072186590951,33133863936280024,449557939142907661,6099570552966630306
%N A232018 Number of n X 3 0..2 arrays with no element less than a strict majority of its horizontal and antidiagonal neighbors.
%H A232018 R. H. Hardin, <a href="/A232018/b232018.txt">Table of n, a(n) for n = 1..210</a>
%F A232018 Empirical: a(n) = 9*a(n-1) + 59*a(n-2) + 62*a(n-3) - 275*a(n-4) - 257*a(n-5) + 146*a(n-6) + 84*a(n-7) for n>8.
%F A232018 Empirical g.f.: x*(9 - 15*x - 273*x^2 - 603*x^3 + 1375*x^4 + 1668*x^5 - 778*x^6 - 504*x^7) / (1 - 9*x - 59*x^2 - 62*x^3 + 275*x^4 + 257*x^5 - 146*x^6 - 84*x^7). - _Colin Barker_, Oct 01 2018
%e A232018 Some solutions for n=5:
%e A232018 ..1..1..1....0..0..0....2..0..0....2..0..0....1..1..1....1..1..0....0..0..2
%e A232018 ..0..0..0....1..0..0....0..0..0....0..2..2....0..0..0....1..0..2....0..0..1
%e A232018 ..0..0..0....0..0..0....1..2..1....0..0..1....0..2..1....0..0..2....0..2..2
%e A232018 ..2..0..1....0..2..0....1..1..0....0..0..0....0..0..0....0..0..0....2..1..1
%e A232018 ..0..0..0....0..0..0....0..0..2....2..0..0....1..0..0....1..0..0....1..1..2
%Y A232018 Column 3 of A232023.
%K A232018 nonn
%O A232018 1,1
%A A232018 _R. H. Hardin_, Nov 17 2013