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A180778 Number of distinct solutions of sum{i=1..7}(x(2i-1)*x(2i)) = 0 (mod n), with x() only in 1..n-1 1

%I

%S 0,0,9,198,2294,19467,126864,674922,2997717,11615754,39660995,

%T 123162204,348412638,920581314,2264397902,5294830516,11692554408,

%U 24858751383,50403391227,99282023930,187902783369,347689331443,621482071507

%N Number of distinct solutions of sum{i=1..7}(x(2i-1)*x(2i)) = 0 (mod n), with x() only in 1..n-1

%C Column 7 of A180782

%H R. H. Hardin, <a href="/A180778/b180778.txt">Table of n, a(n) for n=1..183</a>

%e Solutions for sum of products of 7 1..2 pairs = 0 (mod 3) are

%e (1*1 + 1*1 + 1*1 + 1*1 + 1*1 + 1*2 + 1*2)

%e (1*1 + 1*1 + 1*1 + 1*1 + 1*2 + 1*2 + 2*2)

%e (1*1 + 1*1 + 1*1 + 1*2 + 1*2 + 2*2 + 2*2)

%e (1*1 + 1*1 + 1*2 + 1*2 + 1*2 + 1*2 + 1*2)

%e (1*1 + 1*1 + 1*2 + 1*2 + 2*2 + 2*2 + 2*2)

%e (1*1 + 1*2 + 1*2 + 1*2 + 1*2 + 1*2 + 2*2)

%e (1*1 + 1*2 + 1*2 + 2*2 + 2*2 + 2*2 + 2*2)

%e (1*2 + 1*2 + 1*2 + 1*2 + 1*2 + 2*2 + 2*2)

%e (1*2 + 1*2 + 2*2 + 2*2 + 2*2 + 2*2 + 2*2)

%K nonn

%O 1,3

%A _R. H. Hardin_ Sep 20 2010

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Last modified August 19 07:13 EDT 2022. Contains 356216 sequences. (Running on oeis4.)