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A199906 Number of -5..5 arrays x(0..n-1) of n elements with zero sum, and adjacent elements not equal modulo three (with -1 modulo 3 = 2).

%I A199906 #7 Jun 02 2025 05:25:17
%S A199906 1,8,60,256,1836,12872,77874,547604,3784512,25525476,179010266,
%T A199906 1249682864,8709865930,61360521500,432263649142,3049721406636,
%U A199906 21595190691722,153069769124720,1086568858888600,7726348605601340
%N A199906 Number of -5..5 arrays x(0..n-1) of n elements with zero sum, and adjacent elements not equal modulo three (with -1 modulo 3 = 2).
%C A199906 Column 5 of A199909
%H A199906 R. H. Hardin, <a href="/A199906/b199906.txt">Table of n, a(n) for n = 1..200</a>
%e A199906 Some solutions for n=6
%e A199906 .-1....0...-4...-4...-4....3...-3....0...-2...-4....1....0....5...-3...-5....3
%e A199906 ..3...-5....1....3....3....4....1...-5....2....4....3...-5...-2....5....0...-5
%e A199906 .-1...-3....2....5....1...-4...-4...-3....3....0...-1....5....3....3....1...-3
%e A199906 ..4....4...-2...-3...-1....4....0....2...-1...-4....0...-5...-1...-4....2....4
%e A199906 ..0....3....2...-4....3...-3....1....1....3....4...-5....2...-5...-3...-3....3
%e A199906 .-5....1....1....3...-2...-4....5....5...-5....0....2....3....0....2....5...-2
%K A199906 nonn
%O A199906 1,2
%A A199906 _R. H. Hardin_ Nov 11 2011