%I #9 Oct 20 2018 10:49:00
%S 81,292,1112,3760,13716,46828,169500,582300,2096012,7237244,25932972,
%T 89903068,320993612,1116363900,3974561132,13858016796,49226653068,
%U 171984277180,609825727660,2133983154780,7555901021900,26474357927164
%N Number of (n+1) X (1+1) 0..2 arrays colored with the difference of the maximum and minimum in each 2 X 2 subblock.
%H R. H. Hardin, <a href="/A236048/b236048.txt">Table of n, a(n) for n = 1..210</a>
%F Empirical: a(n) = 9*a(n-2) + 4*a(n-3) + 24*a(n-4) + 12*a(n-5) + 8*a(n-6) for n > 8.
%F Empirical g.f.: x*(81 + 292*x + 383*x^2 + 808*x^3 + 596*x^4 + 560*x^5 + 176*x^6 + 64*x^7) / (1 - 9*x^2 - 4*x^3 - 24*x^4 - 12*x^5 - 8*x^6). - _Colin Barker_, Oct 20 2018
%e Some solutions for n=4:
%e 2 2 2 1 0 1 1 1 1 2 2 2 1 0 0 0 2 2 1 0
%e 2 2 2 2 0 1 1 1 2 1 1 1 0 1 1 2 1 1 2 2
%e 2 1 1 0 1 2 0 0 1 0 1 1 2 2 2 1 1 1 2 1
%e 0 1 0 0 2 1 0 0 0 0 0 0 1 2 0 0 1 2 0 1
%e 0 0 0 2 0 0 1 2 0 2 2 1 0 0 0 1 0 1 1 0
%Y Column 1 of A236055.
%K nonn
%O 1,1
%A _R. H. Hardin_, Jan 18 2014
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