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 A025024 #15 Feb 16 2025 08:32:35 %S A025024 311,622,719,839,1009,1129,1201,1438,1511,1678,1801,2018,2258,2399, %T A025024 2402,2521,3022,3049,3191,3359,3361,3602,3889,4079,4201,4561,4679, %U A025024 4729,4798,4871,5039,5042,5209,5351,5591,5879,5881,6098,6359,6382,6718,6719,6722 %N A025024 Numbers whose least quadratic nonresidue (A020649) is 11. %H A025024 Amiram Eldar, <a href="/A025024/b025024.txt">Table of n, a(n) for n = 1..10000</a> %H A025024 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/QuadraticNonresidue.html">Quadratic Nonresidue</a>. %t A025024 Select[Range[7000], Min @ Complement[Range[# - 1], Mod[Range[#/2]^2, #]] == 11 &] (* _Amiram Eldar_, Oct 31 2020 *) %o A025024 (PARI) residue(n,m)=local(r);r=0;for(i=1,floor(m/2),if(i^2%m==n,r=1));r %o A025024 isA025024(n)=local(a);a=1;forprime(p=2,7,a=a && residue(p,n));a=a && !residue(11,n);a \\ _Michael B. Porter_, Apr 30 2010 %o A025024 (PARI) is(n)=issquare(Mod(2,n)) && issquare(Mod(3,n)) && issquare(Mod(5,n)) && issquare(Mod(7,n)) && !issquare(Mod(11,n)) \\ _Charles R Greathouse IV_, Jan 24 2020 %Y A025024 Cf. A020649, A025020, A025021, A025022, A025023, A025025, A025026, A025027, A025028, A025029. %K A025024 nonn %O A025024 1,1 %A A025024 _David W. Wilson_