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A268794 Number of nX4 0..2 arrays with some element plus some horizontally, vertically or antidiagonally adjacent neighbor totalling two exactly once.

%I A268794 #4 Feb 13 2016 13:42:32
%S A268794 36,234,950,4800,23994,117062,561116,2652936,12405748,57490444,
%T A268794 264428454,1208522850,5493284922,24851601802,111963916212,
%U A268794 502590509990,2248738675490,10032298715910,44640056867750,198161794087570
%N A268794 Number of nX4 0..2 arrays with some element plus some horizontally, vertically or antidiagonally adjacent neighbor totalling two exactly once.
%C A268794 Column 4 of A268798.
%H A268794 R. H. Hardin, <a href="/A268794/b268794.txt">Table of n, a(n) for n = 1..210</a>
%F A268794 Empirical: a(n) = 2*a(n-1) +19*a(n-2) +10*a(n-3) -122*a(n-4) -320*a(n-5) -295*a(n-6) +8*a(n-7) +176*a(n-8) +20*a(n-9) -98*a(n-10) -6*a(n-11) +43*a(n-12) -6*a(n-13) -11*a(n-14) +6*a(n-15) -a(n-16) for n>19
%e A268794 Some solutions for n=4
%e A268794 ..0..1..2..1. .2..2..1..2. .0..0..0..0. .1..2..2..2. .2..2..2..2
%e A268794 ..2..2..2..2. .2..2..2..1. .0..1..0..1. .1..2..2..2. .1..2..2..1
%e A268794 ..1..2..1..2. .1..2..2..2. .0..0..1..0. .2..2..2..1. .2..2..2..2
%e A268794 ..2..2..2..1. .1..2..2..1. .1..0..0..0. .2..2..2..2. .1..1..2..2
%Y A268794 Cf. A268798.
%K A268794 nonn
%O A268794 1,1
%A A268794 _R. H. Hardin_, Feb 13 2016