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%I #10 Feb 12 2018 15:12:14
%S 0,1,18,148,1164,8824,65932,489456,3622896,26780480,197840840,
%T 1461141856,10789799120,79672591776,588291947152,4343817165312,
%U 32073601733504,236822417610560,1748627793559200,12911351644960960,95333587133290624
%N Number of 2 X n arrays of occupancy after each element moves to some horizontal, diagonal or antidiagonal neighbor, without 2-loops.
%C Row 2 of A221351.
%H R. H. Hardin, <a href="/A221352/b221352.txt">Table of n, a(n) for n = 1..40</a>
%F Empirical: a(n) = 11*a(n-1) -26*a(n-2) -10*a(n-3) +34*a(n-4) +14*a(n-5) -16*a(n-6) -8*a(n-7).
%F Empirical g.f.: x^2*(1 + 7*x - 24*x^2 + 14*x^3 + 14*x^4 - 14*x^5) / (1 - 11*x + 26*x^2 + 10*x^3 - 34*x^4 - 14*x^5 + 16*x^6 + 8*x^7). - _Colin Barker_, Feb 12 2018
%e Some solutions for n=3:
%e ..0..3..1....1..3..1....1..1..0....0..1..1....0..3..1....1..1..0....0..1..1
%e ..0..1..1....0..1..0....1..3..0....1..3..0....1..1..0....0..3..1....0..3..1
%K nonn
%O 1,3
%A _R. H. Hardin_, Jan 11 2013
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