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%I #7 Feb 25 2019 09:33:11
%S 2,8,16,36,112,256,608,1680,4064,9920,25984,64320,159232,407296,
%T 1017344,2536704,6420992,16093184,40271872,101471232,254636032,
%U 638328832,1605165056,4029763584,10110525440,25402425344,63780978688,160088997888
%N Number of n X 2 0..1 arrays with each 1 adjacent to 1, 3 or 5 king-move neighboring 1s.
%H R. H. Hardin, <a href="/A296946/b296946.txt">Table of n, a(n) for n = 1..210</a>
%F Empirical: a(n) = 2*a(n-1) + 8*a(n-3) - 12*a(n-4).
%F Empirical g.f.: 2*x*(1 + 2*x - 6*x^3) / (1 - 2*x - 8*x^3 + 12*x^4). - _Colin Barker_, Feb 25 2019
%e Some solutions for n=7:
%e ..0..0. .1..1. .1..1. .1..0. .1..1. .1..1. .0..1. .1..1. .0..0. .0..0
%e ..1..1. .0..0. .0..0. .0..1. .0..0. .0..0. .0..1. .1..1. .0..0. .1..1
%e ..0..0. .1..1. .0..1. .1..1. .0..1. .1..1. .1..1. .1..1. .0..0. .1..1
%e ..1..1. .0..0. .0..1. .1..0. .0..1. .1..1. .1..0. .0..0. .1..1. .0..0
%e ..0..0. .0..0. .0..0. .1..0. .1..1. .0..0. .0..1. .1..1. .1..1. .1..1
%e ..0..0. .0..1. .0..1. .0..0. .0..1. .0..1. .0..0. .0..0. .0..0. .1..1
%e ..1..1. .0..1. .1..0. .1..1. .1..0. .1..0. .0..0. .0..0. .1..1. .1..1
%Y Column 2 of A296952.
%K nonn
%O 1,1
%A _R. H. Hardin_, Dec 22 2017
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