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A180796 Number of distinct solutions of sum{i=1..4}(x(2i-1)*x(2i)) = 0 (mod n), with x() in 0..n-1.

%I A180796 #6 Jun 02 2025 03:06:15
%S A180796 1,9,45,205,620,1957,4507,11171,22146,45350,78661,151695,234757,
%T A180796 405587,621513,995842,1396875,2214555,2949517,4476311,5932188,8399584,
%U A180796 10743228,15648807,19058660,26160160,32743869,43862757,52161089,71513890,82339801
%N A180796 Number of distinct solutions of sum{i=1..4}(x(2i-1)*x(2i)) = 0 (mod n), with x() in 0..n-1.
%C A180796 Column 4 of A180803
%H A180796 R. H. Hardin, <a href="/A180796/b180796.txt">Table of n, a(n) for n=1..376</a>
%e A180796 Solutions for sum of products of 4 0..1 pairs = 0 (mod 2) are
%e A180796 (0*0 + 0*0 + 0*0 + 0*0) (0*0 + 0*0 + 0*0 + 0*1) (0*0 + 0*0 + 0*1 + 0*1)
%e A180796 (0*0 + 0*0 + 1*1 + 1*1) (0*0 + 0*1 + 0*1 + 0*1) (0*0 + 0*1 + 1*1 + 1*1)
%e A180796 (0*1 + 0*1 + 0*1 + 0*1) (0*1 + 0*1 + 1*1 + 1*1) (1*1 + 1*1 + 1*1 + 1*1)
%K A180796 nonn
%O A180796 1,2
%A A180796 _R. H. Hardin_, suggested by _Max Alekseyev_ in the Sequence Fans Mailing List, Sep 20 2010