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 A191088 #16 Jan 19 2016 14:00:32
%S A191088 3,5,43,43,67,67,163,163,163,163,163,163,74093,77683,214037,214037,
%T A191088 214037,2004917,36254563,51599563,96295483,96295483,114148483,
%U A191088 163520117,163520117,261153653,261153653,585811843
%N A191088 Least number k such that the first n primes have Kronecker symbol (p|k) = -1.
%C A191088 This implies, but is not equivalent to, that the first n primes are quadratic non-residues mod k. [Corrected by _M. F. Hasler_, Jan 18 2016]
%C A191088 The first 13 terms are prime. Sequence A191089 is similar, but forces k to be prime.
%C A191088 In case k is restricted to be a prime, the condition (p|k) = -1 becomes equivalent to saying that p is a quadratic non-residue (mod k). - _M. F. Hasler_, Jan 18 2016
%e A191088 a(1) = 3 is the least number k such that prime(1) = 2 is not a square mod k (since for k=1 and k=2, p=2 would be zero, thus a square, mod k).
%e A191088 a(2) = 4 is the least number k such that prime(1) = 2 and prime(2) = 3 are not squares mod k (the only squares mod 4 are 0 = 0^1 = 2^2 and 1 = 1^2 = 3^3 (mod 4); while for k=2, p=2 would be zero, thus a square, and for k=3 this would be the case for p=3).
%t A191088 Table[k = 2; While[Length[Select[Prime[Range[n]], JacobiSymbol[#, k] == -1 &]] < n, k++]; k, {n, 15}]
%o A191088 (PARI) q=2;for(k=3,1e9,forprime(p=2,q,if(kronecker(p,k)>=0,next(2)));print1(k", ");q=nextprime(q+1);k--) \\ _Charles R Greathouse IV_, Oct 10 2011
%Y A191088 Cf. A191089.
%K A191088 nonn
%O A191088 1,1
%A A191088 _T. D. Noe_, May 25 2011
%E A191088 a(16)-a(28) from _Charles R Greathouse IV_, Oct 10 2011