%I #5 Mar 31 2012 12:36:11
%S 1,2,4,15,58,245,1082,5020,24040,118154,592332,3019280,15604848,
%T 81614541,431227650,2298833499,12350952158,66818754504,363727676848,
%U 1990946917066,10952512200610,60525264890259,335856363303010,1870732844007387
%N Number of nondecreasing arrangements of n numbers in -(n-1)..(n-1) with sum zero and not more than two numbers equal
%C Column 1 of A188236
%H R. H. Hardin, <a href="/A188228/b188228.txt">Table of n, a(n) for n = 1..31</a>
%e All solutions for n=4
%e .-3...-1...-2...-3...-3...-2...-1...-2...-3...-2...-3...-1...-2...-2...-3
%e .-1...-1....0....0...-2...-2...-1...-2...-3....0....0....0...-1...-1...-1
%e ..1....0....1....1....2....1....1....2....3....0....0....0....0....1....2
%e ..3....2....1....2....3....3....1....2....3....2....3....1....3....2....2
%K nonn
%O 1,2
%A _R. H. Hardin_ Mar 24 2011
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