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%I #7 Nov 25 2018 09:41:51
%S 37,147,526,1844,6544,23334,83126,295938,1053609,3751373,13356805,
%T 47556710,169324797,602878211,2146538499,7642716637,27211772110,
%U 96887085837,344964943222,1228242247433,4373137177399,15570486043677
%N Number of (n+1) X (1+1) 0..2 arrays with no 2 X 2 subblock having the maximum of its diagonal elements greater than the absolute difference of its antidiagonal elements.
%H R. H. Hardin, <a href="/A251106/b251106.txt">Table of n, a(n) for n = 1..210</a>
%F Empirical: a(n) = 5*a(n-1) - 8*a(n-2) + 13*a(n-3) - 12*a(n-4) + 9*a(n-5) - 5*a(n-6) + a(n-7).
%F Empirical g.f.: x*(37 - 38*x + 87*x^2 - 91*x^3 + 65*x^4 - 41*x^5 + 10*x^6) / ((1 + x^2)*(1 - 5*x + 7*x^2 - 8*x^3 + 5*x^4 - x^5)). - _Colin Barker_, Nov 25 2018
%e Some solutions for n=4:
%e ..0..2....0..2....2..2....1..1....0..2....1..2....1..1....0..2....0..0....1..1
%e ..1..0....0..0....0..2....0..0....0..1....1..0....0..0....1..0....0..0....0..0
%e ..2..2....1..1....0..2....2..2....0..0....2..0....1..0....1..1....2..2....1..0
%e ..0..0....0..1....0..2....0..2....0..0....2..0....2..2....0..0....0..1....1..1
%e ..2..0....1..0....1..0....0..0....2..2....2..2....0..2....2..0....2..0....0..0
%Y Column 1 of A251113.
%K nonn
%O 1,1
%A _R. H. Hardin_, Nov 30 2014
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