This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A025026 #18 Feb 16 2025 08:32:35
%S A025026 1559,2999,3118,5998,6551,8089,8761,13102,13729,14759,16178,16631,
%T A025026 17522,18119,19009,21121,21961,23399,24049,27431,27458,27551,28081,
%U A025026 29518,31249,33262,33289,33479,35281,35591,36238,36791,38018,42242,43391,43922,43991
%N A025026 Numbers whose least quadratic nonresidue (A020649) is 17.
%H A025026 Amiram Eldar, <a href="/A025026/b025026.txt">Table of n, a(n) for n = 1..10000</a>
%H A025026 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/QuadraticNonresidue.html">Quadratic Nonresidue</a>.
%t A025026 Select[Range[20000], Min @ Complement[Range[# - 1], Mod[Range[#/2]^2, #]] == 17 &] (* _Amiram Eldar_, Oct 31 2020 *)
%o A025026 (PARI) residue(n,m)=local(r);r=0;for(i=1,floor(m/2),if(i^2%m==n,r=1));r
%o A025026 isA025026(n)={local(a);a=1;forprime(p=2,13,a=a && residue(p,n));a=a && !residue(17,n);a} \\ _Michael B. Porter_, Apr 30 2010
%o A025026 (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)) && !issquare(Mod(17,n)) \\ _Charles R Greathouse IV_, Jan 24 2020
%Y A025026 Cf. A020649, A025020, A025021, A025022, A025023, A025024, A025025, A025027, A025028, A025029.
%K A025026 nonn
%O A025026 1,1
%A A025026 _David W. Wilson_