%I #11 Jun 12 2021 16:03:29
%S 0,0,0,0,0,1,0,3,1,6,0,13,0,15,7,21,0,37,0,39,16,45,0,73,6,66,28,81,0,
%T 130,0,105,46,120,21,181,0,153,67,189,0,262,0,213,118,231,0,337,15,
%U 306,121,303,0,433,51,369,154,378,0,583,0,435,217,465
%N Number of ordered pairs (i,j) with 0 < i < j < n such that gcd(i,j,n) > 1.
%C A 4-regular circulant graph of order n, C(n,i,j), is connected if and only if gcd(n,i,j) = 1, where 0 < i < j < n.
%H Paul Theo Meijer, <a href="https://core.ac.uk/display/56367757">Connectivities and diameters of circulant graphs</a>
%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/CirculantGraph.html">Circulant Graph</a>
%t npairs[n_]:=Module[{k=0},
%t Do[Do[
%t If[GCD[i,j,n]>1,k++]
%t ,{i,1,j-1}],{j,2,n-1}];
%t Return[k]];
%t Table[npairs[n],{n,1,60}]
%Y Cf. A000741, A075545, A344517.
%K nonn
%O 1,8
%A _Andres Cicuttin_, May 23 2021