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%I #5 Mar 31 2012 12:36:11
%S 1,3,7,30,119,527,2395,11376,55368,275735,1397063,7185356,37419881,
%T 196993233,1046785509,5608211846,30264466262,164375822152,
%U 897938065590,4930713542112,27202861579741,150721902660263,838367664692809
%N Number of nondecreasing arrangements of n numbers in -n..n with sum zero and not more than two numbers equal
%C Column 2 of A188236
%H R. H. Hardin, <a href="/A188229/b188229.txt">Table of n, a(n) for n = 1..31</a>
%e Some solutions for n=4
%e .-3...-2...-3...-2...-3...-4...-4...-4...-3...-4...-1...-2...-4...-3...-3...-1
%e .-2...-2...-3....0...-1...-2...-4....0....0...-3....0...-1....0...-3...-1...-1
%e ..2....0....2....0....2....2....4....0....1....3....0...-1....2....3....0....0
%e ..3....4....4....2....2....4....4....4....2....4....1....4....2....3....4....2
%K nonn
%O 1,2
%A _R. H. Hardin_ Mar 24 2011
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