A096634 - OEIS

%I #11 Apr 18 2023 08:29:15

%S 3,5,3,5,3,7,3,11,3,5,3,7,3,7,3,5,3,3,7,5,3,5,13,3,3,11,3,5,3,7,3,3,

%T 13,5,5,3,3,3,7,5,5,3,5,3,7,3,7,5,3,5,3,5,3,5,3,3,3,11,11,5,3,13,5,3,

%U 17,3,7,5,3,3,7,11,7,3,3,5,3,3,3,7,5,3,3,3,11,3,13,5,3,3,7,3,3,11,5,3,3,5,3

%N Let p = n-th prime == 5 (mod 8) (A007521); a(n) = smallest prime q such that p is not a square mod q.

%H Robert Israel, <a href="/A096634/b096634.txt">Table of n, a(n) for n = 1..10000</a>

%p g:= proc(n) local p;

%p   p:= 1;

%p   do

%p     p:= nextprime(p);

%p     if numtheory:-quadres(n,p) = -1 then return p fi

%p   od

%p end proc:

%p map(g, select(isprime, [seq(i,i=5..10000,8)])); # _Robert Israel_, Apr 17 2023

%t f[n_] := Block[{k = 2}, While[ JacobiSymbol[n, Prime[k]] == 1, k++ ]; Prime[k]]; f /@ Select[ Prime[ Range[435]], Mod[ #, 8] == 5 &]

%Y Cf. A094928, A096633, A096635, A096638.

%K nonn

%O 1,1

%A _Robert G. Wilson v_, Jun 24 2004