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%I #12 Apr 07 2017 12:58:22
%S 1,22,76,430,767,1072,1577,2675,3930,4587,6520,7518,10761,12258,14809,
%T 19527,23025,26811,29148,35247,41900,47844,52771,57938,61377,66944,
%U 73845,76568,79940,83941,94088,102237,104781,114744,117470,134498,152678,161389,167881,181249,193377,204075,221598,228185
%N Let p = n-th prime == 3 mod 8; a(n) = sum of quadratic residues mod p.
%H Vincenzo Librandi, <a href="/A282723/b282723.txt">Table of n, a(n) for n = 1..2500</a>
%H Aebi, Christian, and Grant Cairns. <a href="http://arxiv.org/abs/1512.00896">Sums of Quadratic residues and nonresidues</a>, arXiv preprint arXiv:1512.00896 (2015).
%p with(numtheory):
%p Ql:=[]; Qu:=[]; Q:=[]; Nl:=[]; Nu:=[]; N:=[]; Th:=[];
%p for i1 from 1 to 300 do
%p p:=ithprime(i1);
%p if (p mod 8) = 3 then
%p ql:=0; qu:=0; q:=0; nl:=0; nu:=0; n:=0;
%p for j from 1 to p-1 do
%p if legendre(j,p)=1 then
%p q:=q+j;
%p if j<p/2 then ql:=ql+j; else qu:=qu+j; fi;
%p else
%p n:=n+j;
%p if j<p/2 then nl:=nl+j; else nu:=nu+j; fi;
%p fi;
%p od;
%p Ql:=[op(Ql),ql];
%p Qu:=[op(Qu),qu];
%p Q:=[op(Q),q];
%p Nl:=[op(Nl),nl];
%p Nu:=[op(Nu),nu];
%p N:=[op(N),n];
%p Th:=[op(Th),q+ql];
%p fi;
%p od:
%p Ql; Qu; Q; Nl; Nu; N; Th; # A282721 - A282727
%t Table[Table[Mod[a^2, p], {a, 1, (p-1)/2}]//Total, {p, Select[Prime[Range[100]], Mod[#, 8] == 3 &]}] (* _Vincenzo Librandi_, Feb 21 2017 *)
%Y Cf. A282035-A282043 and A282721-A282727.
%K nonn
%O 1,2
%A _N. J. A. Sloane_, Feb 20 2017
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