%I #11 Mar 03 2018 05:35:40
%S 2,12,50,188,724,2820,10960,42544,165176,641376,2490416,9669968,
%T 37547296,145791744,566092192,2198069056,8534842304,33139784256,
%U 128677866752,499640952320,1940046781312,7532972421120,29249641835776,113572903188736
%N Number of n X 2 binary arrays with every one adjacent to another one horizontally, diagonally, antidiagonally or vertically.
%C Column 2 of A202795.
%H R. H. Hardin, <a href="/A202789/b202789.txt">Table of n, a(n) for n = 1..210</a>
%F Empirical: a(n) = 4*a(n-1) - 2*a(n-2) + 6*a(n-3).
%F Empirical g.f.: 2*x*(1 + 2*x + 3*x^2) / (1 - 4*x + 2*x^2 - 6*x^3). - _Colin Barker_, Mar 03 2018
%e Some solutions for n=5:
%e 1 1 1 1 1 1 1 1 1 1 0 0 1 1 0 1 0 0 0 1
%e 0 0 0 1 1 1 1 0 1 1 1 0 0 1 1 1 1 1 0 1
%e 0 1 1 1 1 1 1 1 1 0 0 1 1 1 1 0 1 1 1 0
%e 1 0 1 0 0 1 0 0 1 0 1 0 0 1 0 0 1 1 0 0
%e 1 0 1 0 1 0 1 1 0 1 0 0 1 0 0 0 1 0 1 1
%Y Cf. A202795.
%K nonn
%O 1,1
%A _R. H. Hardin_, Dec 24 2011