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A231645 Number of n X 2 0..2 arrays with no element less than a strict majority of its horizontal and vertical neighbors.

%I A231645 #8 Mar 18 2018 06:59:27
%S A231645 3,35,104,341,1189,4040,13560,45803,155131,524683,1773770,5998876,
%T A231645 20290918,68629108,232120783,785115525,2655576210,8982247095,
%U A231645 30381769982,102764504913,347595681724,1175726561166,3976846922803,13451535863780
%N A231645 Number of n X 2 0..2 arrays with no element less than a strict majority of its horizontal and vertical neighbors.
%C A231645 Column 2 of A231651.
%H A231645 R. H. Hardin, <a href="/A231645/b231645.txt">Table of n, a(n) for n = 1..210</a>
%F A231645 Empirical: a(n) = 6*a(n-1) - 12*a(n-2) + 19*a(n-3) - 32*a(n-4) + 15*a(n-5) - 13*a(n-6) + 13*a(n-7) + 10*a(n-8) + 7*a(n-9) + 5*a(n-10) + a(n-11) for n>12.
%F A231645 Empirical g.f.: x*(3 + 17*x - 70*x^2 + 80*x^3 - 178*x^4 + 97*x^5 - 49*x^6 + 100*x^7 + 73*x^8 + 48*x^9 + 31*x^10 + 6*x^11) / (1 - 6*x + 12*x^2 - 19*x^3 + 32*x^4 - 15*x^5 + 13*x^6 - 13*x^7 - 10*x^8 - 7*x^9- 5*x^10 - x^11). - _Colin Barker_, Mar 18 2018
%e A231645 Some solutions for n=3:
%e A231645 ..1..1....2..2....0..0....1..1....1..2....0..0....0..0....0..0....2..0....0..1
%e A231645 ..2..1....1..1....0..2....2..2....0..0....2..1....0..0....0..0....2..0....0..0
%e A231645 ..1..1....1..1....0..0....1..1....0..0....0..0....2..1....1..2....0..0....1..0
%Y A231645 Cf. A231651.
%K A231645 nonn
%O A231645 1,1
%A A231645 _R. H. Hardin_, Nov 12 2013