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%I #5 Mar 31 2012 12:36:46
%S 1,81,101,1357,7463,80065,490879,3697331,28156261,240962805,
%T 1907124597,16026836953,133898693111,1130246507329,9448228560881,
%U 79776887571979,675881669398761,5767799951404371,49328839761741989,423380827767076411
%N Number of -4..4 circular arrays x(0..n+1) of n+2 elements with zero sums of x(i) and x(i)*x((i+1) mod (n+2))
%C Column 4 of A202006
%H R. H. Hardin, <a href="/A202002/b202002.txt">Table of n, a(n) for n = 1..53</a>
%e Some solutions for n=5
%e ..3....2....3...-1....4...-4....2....3...-3...-1....3....2...-2....4...-4...-2
%e .-2...-1....3....2....2....0....4...-2...-1....1...-2...-3...-1....4...-4...-2
%e .-4....2...-4....0...-3....4...-3...-4....2...-4....0...-1....1...-4....0....3
%e ..2....0...-2...-2...-4....0...-3....1...-2....0...-1....0...-2...-3....3....2
%e .-3...-2....1...-2....1....0...-2....1....3....3...-4...-4....0....2...-2...-1
%e ..0...-2...-3....1....2....4....3....1....3....2....2....3....3...-3....3...-1
%e ..4....1....2....2...-2...-4...-1....0...-2...-1....2....3....1....0....4....1
%K nonn
%O 1,2
%A _R. H. Hardin_ Dec 07 2011