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%I #8 Aug 08 2018 15:09:03
%S 2,8,40,180,772,3264,13634,56456,232150,949520,3867132,15696660,
%T 63539998,256648344,1034811554,4166389484,16755205300,67316907560,
%U 270245535066,1084211943720,4347515085838,17425292086536,69817530875564
%N Equals one maps: number of n X 2 binary arrays indicating the locations of corresponding elements equal to exactly one of their king-move neighbors in a random 0..3 n X 2 array.
%C Column 2 of A221590.
%H R. H. Hardin, <a href="/A221587/b221587.txt">Table of n, a(n) for n = 1..210</a>
%F Empirical: a(n) = 6*a(n-1) - 3*a(n-2) - 22*a(n-3) + 7*a(n-4) + 4*a(n-5) for n>8.
%F Empirical g.f.: 2*x*(1 - 2*x - x^2 + 4*x^3 - 13*x^4 - 6*x^5 + 7*x^6 + 4*x^7) / ((1 - 4*x)*(1 + x - x^2)*(1 - 3*x - x^2)). - _Colin Barker_, Aug 08 2018
%e Some solutions for n=3:
%e ..1..1....0..1....1..0....0..1....0..0....0..0....0..1....0..1....1..0....0..0
%e ..0..0....1..0....0..1....0..1....1..0....0..1....0..0....0..0....1..1....0..1
%e ..1..1....1..1....1..1....0..0....1..1....1..1....0..0....0..1....1..0....0..1
%Y Cf. A221590.
%K nonn
%O 1,1
%A _R. H. Hardin_, Jan 20 2013
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