%I #13 Oct 31 2020 04:35:45
%S 479,958,1151,1319,2302,2351,2638,2689,3529,3671,3911,4702,4751,4919,
%T 5378,5519,5569,6599,7058,7342,7559,7561,7681,7822,8951,9241,9502,
%U 9601,9719,9769,9838,11038,11138,12049,12239,12721,12911,13151,13198,14159
%N Numbers whose least quadratic nonresidue (A020649) is 13.
%H Amiram Eldar, <a href="/A025025/b025025.txt">Table of n, a(n) for n = 1..10000</a>
%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/QuadraticNonresidue.html">Quadratic Nonresidue</a>.
%t Select[Range[14000], Min @ Complement[Range[# - 1], Mod[Range[#/2]^2, #]] == 13 &] (* _Amiram Eldar_, Oct 31 2020 *)
%o (PARI) residue(n,m)=local(r);r=0;for(i=1,floor(m/2),if(i^2%m==n,r=1));r
%o isA025025(n)=local(a);a=1;forprime(p=2,11,a=a && residue(p,n));a=a && !residue(13,n);a \\ _Michael B. Porter_, Apr 30 2010
%o (PARI) is(n)=issquare(Mod(2,n)) && issquare(Mod(3,n)) && issquare(Mod(5,n)) && issquare(Mod(7,n)) && issquare(Mod(11,n)) && !issquare(Mod(13,n)) \\ _Charles R Greathouse IV_, Jan 24 2020
%Y Cf. A020649, A025020, A025021, A025022, A025023, A025024, A025026, A025027, A025028, A025029.
%K nonn
%O 1,1
%A _David W. Wilson_