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%I #8 Apr 09 2018 08:50:35
%S 81,83,86,92,102,122,158,230,366,638,1166,2222,4302,8462,16718,33230,
%T 66126,131918,263246,525902,1050702,2100302,4198478,8394830,16785486,
%U 33566798,67125326,134242382,268468302,536920142,1073807438,2147582030
%N 1/4 the number of (n+1) X 8 binary arrays with all 2 X 2 subblock sums the same.
%C Column 7 of A183986.
%H R. H. Hardin, <a href="/A183984/b183984.txt">Table of n, a(n) for n = 1..200</a>
%F Empirical: a(n) = 3*a(n-1) - 6*a(n-3) + 4*a(n-4).
%F Conjectures from _Colin Barker_, Apr 09 2018: (Start)
%F G.f.: x*(81 - 160*x - 163*x^2 + 320*x^3) / ((1 - x)*(1 - 2*x)*(1 - 2*x^2)).
%F a(n) = 3*2^(n/2-1) + 2^(n-1) + 78 for n even.
%F a(n) = 2^(n-1) + 2^((n+1)/2) + 78 for n odd.
%F (End)
%e Some solutions for 5 X 8.
%e ..0..0..1..1..1..1..0..1....1..1..0..1..1..0..1..1....1..0..1..0..1..0..1..0
%e ..1..1..0..0..0..0..1..0....0..0..1..0..0..1..0..0....1..1..1..1..1..1..1..1
%e ..0..0..1..1..1..1..0..1....1..1..0..1..1..0..1..1....0..1..0..1..0..1..0..1
%e ..1..1..0..0..0..0..1..0....0..0..1..0..0..1..0..0....1..1..1..1..1..1..1..1
%e ..0..0..1..1..1..1..0..1....1..1..0..1..1..0..1..1....1..0..1..0..1..0..1..0
%Y Cf. A183986.
%K nonn
%O 1,1
%A _R. H. Hardin_, Jan 08 2011
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