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%I #3 Mar 31 2012 12:35:46
%S 0,0,5,14,42,119,253,526,944,1702,2655,4510,6284,9867,13519,19980,
%T 25128,37286,44562,63802,76850,102370,118591,168208,183320,241554,
%U 279852,359754,387016,528861,543620,712450,780810,953120,1025355,1360255
%N Number of distinct solutions of sum{i=1..3}(x(2i-1)*x(2i)) = 0 (mod n), with x() only in 1..n-1
%C Column 3 of A180782
%H R. H. Hardin, <a href="/A180774/b180774.txt">Table of n, a(n) for n=1..447</a>
%e Solutions for sum of products of 3 1..3 pairs = 0 (mod 4) are
%e (1*1 + 1*1 + 1*2) (1*1 + 1*1 + 2*3) (1*1 + 1*2 + 3*3) (1*1 + 1*3 + 2*2)
%e (1*1 + 2*3 + 3*3) (1*2 + 1*2 + 2*2) (1*2 + 1*3 + 1*3) (1*2 + 2*2 + 2*3)
%e (1*2 + 3*3 + 3*3) (1*3 + 1*3 + 2*3) (1*3 + 2*2 + 3*3) (2*2 + 2*2 + 2*2)
%e (2*2 + 2*3 + 2*3) (2*3 + 3*3 + 3*3)
%K nonn
%O 1,3
%A _R. H. Hardin_ Sep 20 2010
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