%I #11 Dec 25 2023 17:42:15
%S 1,2,-1,8,41,-2,-1,32,81,82,-1,-8,313,-2,-41,128,545,162,-1,328,1,-2,
%T -1,-32,1425,626,-81,-8,1625,-82,-1,512,1,1090,-41,648,2665,-2,-313,
%U 1312,3281,2,-1,-8,3321,-2,-1,-128,2401,2850,-545,2504,5513,-162,-41,-32,1,3250,-1,-328,7321
%N Sum{gcd(k^2 + t^2, n) * cos(2*Pi*(k^2 + t^2)/n): 0<k,t<=n}
%t GGG[n_] := Sum[GCD[k^2 + t^2, n] Cos[2 Pi (k^2 + t^2)/n], {k, 1, n}, {t, 1, n}];Table[Round[GGG[n]], {n, 1, 111}]
%K sign
%O 1,2
%A _José María Grau Ribas_, Mar 22 2014