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%I #11 Feb 12 2019 15:19:52
%S 0,4,8,28,80,252,776,2356,7200,21836,66104,199652,601424,1808252,
%T 5426024,16253460,48608384,145152940,432853144,1289129028,3834701744,
%U 11394112476,33820033480,100286009972,297101633248,879410116620,2600884035320
%N Number of n X 2 0..2 arrays with no element unequal to a strict majority of its horizontal, vertical and antidiagonal neighbors, with the exception of exactly one element, and with new values introduced in order 0 sequentially upwards.
%H R. H. Hardin, <a href="/A280118/b280118.txt">Table of n, a(n) for n = 1..210</a>
%F Empirical: a(n) = 2*a(n-1) + 7*a(n-2) - 24*a(n-4) - 32*a(n-5) - 16*a(n-6) for n>8.
%F Empirical g.f.: 4*x^2*(1 - 4*x^2 - 8*x^3 - 2*x^4 + 8*x^5 + 8*x^6) / (1 - x - 4*x^2 - 4*x^3)^2. - _Colin Barker_, Feb 12 2019
%e Some solutions for n=4:
%e ..0..1. .0..0. .0..0. .0..0. .0..0. .0..0. .0..0. .0..0. .0..0. .0..0
%e ..1..1. .1..0. .0..0. .0..1. .0..1. .0..1. .0..1. .0..1. .0..0. .1..1
%e ..1..0. .0..0. .0..0. .2..2. .1..1. .1..1. .0..0. .1..1. .0..0. .1..1
%e ..0..0. .0..0. .0..1. .2..2. .1..0. .2..1. .0..0. .1..2. .1..1. .1..1
%Y Column 2 of A280124.
%K nonn
%O 1,2
%A _R. H. Hardin_, Dec 26 2016
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