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%I #7 May 03 2023 21:14:45
%S 1,9,37,179,996,4740,21259,96524,443793,2054180,9533062,44194763,
%T 204545507,946059367,4375861741,20244334715,93671407936,433436316256,
%U 2005547859261,9279593479796,42935853340895,198660544800120
%N Number of n X 6 binary arrays with each 1 adjacent to exactly two other 1's.
%C Column 6 of A183328.
%H R. H. Hardin, <a href="/A183327/b183327.txt">Table of n, a(n) for n = 1..200</a>
%F Empirical: a(n)=7*a(n-1)-18*a(n-2)+38*a(n-3)-48*a(n-4)+110*a(n-5)-30*a(n-6)+13*a(n-7)+12*a(n-8)-168*a(n-9)+12*a(n-10)+396*a(n-11)+2076*a(n-12)-2107*a(n-13)-11936*a(n-14)-23630*a(n-15)-11374*a(n-16)+33929*a(n-17)+86596*a(n-18)+85928*a(n-19)-5767*a(n-20)-137160*a(n-21)-186375*a(n-22)-82400*a(n-23)+98660*a(n-24)+206026*a(n-25)+154539*a(n-26)+271*a(n-27)-129682*a(n-28)-144333*a(n-29)-59907*a(n-30)+31467*a(n-31)+61883*a(n-32)+37532*a(n-33)+5039*a(n-34)-7723*a(n-35)-5583*a(n-36)-944*a(n-37)+520*a(n-38)+332*a(n-39)+24*a(n-40)-32*a(n-41).
%e Some solutions for 4 X 6
%e ..0..1..1..1..1..1....0..0..0..0..0..0....0..1..1..1..1..1....0..1..1..1..1..0
%e ..0..1..0..0..0..1....0..0..0..1..1..1....0..1..0..0..0..1....1..1..0..0..1..1
%e ..0..1..1..0..0..1....0..0..0..1..0..1....0..1..0..0..1..1....1..0..0..0..0..1
%e ..0..0..1..1..1..1....0..0..0..1..1..1....0..1..1..1..1..0....1..1..1..1..1..1
%Y Cf. A183328.
%K nonn
%O 1,2
%A _R. H. Hardin_, Jan 03 2011
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