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%I #6 Mar 31 2012 12:36:37
%S 2,4,4,10,22,34,66,138,250,472,944,1806,3450,6772,13172,25478,49794,
%T 97348,189772,371246,727506,1424586,2793034,5483342,10766950,21154424,
%U 41599648,81840866,161080918,317230034,625030514,1231964394,2429323642
%N Number of -1..1 arrays x(0..n+1) of n+2 elements with zero sum and no two neighbors summing to zero
%C Column 1 of A199832
%H R. H. Hardin, <a href="/A199825/b199825.txt">Table of n, a(n) for n = 1..200</a>
%e All solutions for n=3
%e .-1....0....0....1
%e .-1....1...-1....1
%e ..0....0....0....0
%e ..1...-1....1...-1
%e ..1....0....0...-1
%K nonn
%O 1,1
%A _R. H. Hardin_ Nov 11 2011