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A282726 Let p = n-th prime == 3 mod 8; a(n) = sum of quadratic nonresidues mod p . 2
2, 33, 95, 473, 944, 1139, 1826, 2996, 4585, 5004, 6683, 8413, 11394, 13393, 16566, 20376, 23946, 27804, 30883, 36384, 45671, 50059, 56040, 62357, 62874, 69559, 75486, 81635, 82795, 88050, 97183, 104166, 112030, 118159, 120925, 138193, 156613, 167066, 173670, 187262, 196026, 206796, 226333, 242750 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Vincenzo Librandi, Table of n, a(n) for n = 1..2500

Aebi, Christian, and Grant Cairns. Sums of Quadratic residues and nonresidues, arXiv preprint arXiv:1512.00896 (2015).

MAPLE

with(numtheory):

Ql:=[]; Qu:=[]; Q:=[]; Nl:=[]; Nu:=[]; N:=[]; Th:=[];

for i1 from 1 to 300 do

p:=ithprime(i1);

if (p mod 8) = 3 then

ql:=0; qu:=0; q:=0; nl:=0; nu:=0; n:=0;

for j from 1 to p-1 do

if legendre(j, p)=1 then

q:=q+j;

if j<p/2 then ql:=ql+j; else qu:=qu+j; fi;

else

n:=n+j;

if j<p/2 then nl:=nl+j; else nu:=nu+j; fi;

fi;

od;

Ql:=[op(Ql), ql];

Qu:=[op(Qu), qu];

Q:=[op(Q), q];

Nl:=[op(Nl), nl];

Nu:=[op(Nu), nu];

N:=[op(N), n];

Th:=[op(Th), q+ql];

fi;

od:

Ql; Qu; Q; Nl; Nu; N; Th; # A282721 - A282727

MATHEMATICA

Table[Table[Mod[a^2, p/2], {a, 1, (p-1)}]//Total, {p, Select[Prime[ Range[ 200]], Mod[#, 8] == 3 &]}] (* Vincenzo Librandi, Feb 22 2017 *)

CROSSREFS

Cf. A282035-A282043 and A282721-A282727.

Sequence in context: A342620 A065647 A041127 * A097978 A334197 A156369

Adjacent sequences:  A282723 A282724 A282725 * A282727 A282728 A282729

KEYWORD

nonn

AUTHOR

N. J. A. Sloane, Feb 20 2017

STATUS

approved

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Last modified June 21 16:23 EDT 2021. Contains 345365 sequences. (Running on oeis4.)