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%I #7 Jun 22 2021 14:21:34
%S 1,6,42,152,804,5016,24864,139148,814776,4509164,25781576,149525280,
%T 856571710,4954153908,28801991844,167153096856,973462118580,
%U 5682734337828,33191217303840,194193233863080,1137757795417530
%N Number of -4..4 arrays x(0..n-1) of n elements with zero sum, and adjacent elements not equal modulo three (with -1 modulo 3 = 2).
%C Column 4 of A199909.
%H R. H. Hardin, <a href="/A199905/b199905.txt">Table of n, a(n) for n = 1..200</a>
%e Some solutions for n=6
%e ..0....3....1....4...-4....4....1....1....2...-2....3....4...-4...-3....2...-2
%e ..2....1...-1...-3....1...-1....0....2...-2....3...-1...-1....4....2...-2....0
%e .-2...-4....3...-2...-3....3....2...-2....0...-4...-2...-2...-1....1....0....2
%e .-4....1....4...-1....1....1...-2....0....2...-3....2...-4....1....0....1....0
%e ..1...-1...-3....3....2...-4...-4...-1....1....2...-3....4...-1....1...-1....4
%e ..3....0...-4...-1....3...-3....3....0...-3....4....1...-1....1...-1....0...-4
%Y Cf. A199909.
%K nonn
%O 1,2
%A _R. H. Hardin_ Nov 11 2011
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