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%I #3 Mar 31 2012 12:35:46
%S 0,0,0,1,11,409,6946,108997,1113650,9684748,64448228,375427744,
%T 1820591506,7980182839,30660616489,109065451832,351179673979,
%U 1065973101574,2992063116800,8019394451018,20182278132284,48949438473158
%N Number of distinct solutions of sum{i=1..9}(x(2i-1)*x(2i)) = 0 (mod n), with x() only in 2..n-2
%C Column 9 of A180823
%H R. H. Hardin, <a href="/A180821/b180821.txt">Table of n, a(n) for n=1..183</a>
%e Solutions for sum of products of 9 2..3 pairs = 0 (mod 5) are
%e (2*2 + 2*2 + 2*2 + 2*2 + 2*2 + 2*2 + 2*2 + 2*3 + 2*3)
%e (2*2 + 2*2 + 2*2 + 2*2 + 2*2 + 2*2 + 2*3 + 2*3 + 3*3)
%e (2*2 + 2*2 + 2*2 + 2*2 + 2*2 + 2*3 + 2*3 + 3*3 + 3*3)
%e (2*2 + 2*2 + 2*2 + 2*2 + 2*3 + 2*3 + 3*3 + 3*3 + 3*3)
%e (2*2 + 2*2 + 2*2 + 2*3 + 2*3 + 3*3 + 3*3 + 3*3 + 3*3)
%e (2*2 + 2*2 + 2*3 + 2*3 + 2*3 + 2*3 + 2*3 + 2*3 + 2*3)
%e (2*2 + 2*2 + 2*3 + 2*3 + 3*3 + 3*3 + 3*3 + 3*3 + 3*3)
%e (2*2 + 2*3 + 2*3 + 2*3 + 2*3 + 2*3 + 2*3 + 2*3 + 3*3)
%e (2*2 + 2*3 + 2*3 + 3*3 + 3*3 + 3*3 + 3*3 + 3*3 + 3*3)
%e (2*3 + 2*3 + 2*3 + 2*3 + 2*3 + 2*3 + 2*3 + 3*3 + 3*3)
%e (2*3 + 2*3 + 3*3 + 3*3 + 3*3 + 3*3 + 3*3 + 3*3 + 3*3)
%K nonn
%O 1,5
%A _R. H. Hardin_ Sep 20 2010
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