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A231126 Number of (n+1) X (3+1) white-square subarrays of 0..2 arrays with no element equal to a strict majority of its diagonal and antidiagonal neighbors, with values 0..2 introduced in row major order.

%I A231126 #7 Mar 18 2018 06:22:59
%S A231126 6,40,308,2260,16812,124644,924900,6862052,50913012,377747700,
%T A231126 2802692276,20794524084,154284599124,1144711823796,8493168927828,
%U A231126 63014915159220,467538037568404,3468890119531892,25737368287958996,190957944347003188
%N A231126 Number of (n+1) X (3+1) white-square subarrays of 0..2 arrays with no element equal to a strict majority of its diagonal and antidiagonal neighbors, with values 0..2 introduced in row major order.
%C A231126 Column 3 of A231131.
%H A231126 R. H. Hardin, <a href="/A231126/b231126.txt">Table of n, a(n) for n = 1..210</a>
%F A231126 Empirical: a(n) = 7*a(n-1) + 8*a(n-2) - 32*a(n-3) - 38*a(n-4) + 40*a(n-5) + 56*a(n-6) - 16*a(n-7) - 16*a(n-8).
%F A231126 Empirical g.f.: 2*x*(3 - x - 10*x^2 - 12*x^3 + 18*x^4 + 8*x^5 - 8*x^6) / (1 - 7*x - 8*x^2 + 32*x^3 + 38*x^4 - 40*x^5 - 56*x^6 + 16*x^7 + 16*x^8). - _Colin Barker_, Mar 18 2018
%e A231126 Some solutions for n=5:
%e A231126 ..0..x..0..x....0..x..0..x....0..x..1..x....0..x..1..x....0..x..0..x
%e A231126 ..x..1..x..2....x..1..x..2....x..2..x..0....x..2..x..2....x..1..x..0
%e A231126 ..2..x..1..x....2..x..1..x....0..x..1..x....0..x..2..x....2..x..2..x
%e A231126 ..x..0..x..2....x..0..x..0....x..0..x..1....x..1..x..0....x..0..x..2
%e A231126 ..1..x..2..x....1..x..1..x....1..x..2..x....1..x..2..x....0..x..1..x
%e A231126 ..x..2..x..1....x..0..x..0....x..1..x..1....x..2..x..1....x..2..x..2
%Y A231126 Cf. A231131.
%K A231126 nonn
%O A231126 1,1
%A A231126 _R. H. Hardin_, Nov 04 2013