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 A092581 #10 Mar 29 2015 19:10:50
%S A092581 2,3,5,7,11,13,19,23,31,37,43,47,59,61,67,71,79,83,89,101,103,107,109,
%T A092581 127,131,137,149,151,157,163,167,179,181,191,199,227,229,239,251,257,
%U A092581 263,271,277,283,307,311,331,347,349,359,367,373,379,383,409,431,439
%N A092581 a(n) is the least prime such that a(n-1) is a quadratic non-residue of a(n).
%D A092581 Paulo Ribenboim, "The Little Book of Big Primes", Springer-Verlag, 1991, p. 28.
%H A092581 T. D. Noe, <a href="/A092581/b092581.txt">Table of n, a(n) for n=1..1000</a>
%F A092581 "If p>2 does not divide a and if there exists an integer b such that a is congruent to b^2 (mod p), then a is called a quadratic residue modulo p; otherwise, it is a nonquadratic residue modulo p". (p. 28, Ribenboim)
%t A092581 first Needs[ "NumberTheory`NumberTheoryFunctions`" ] then f[n_] := Block[{k = PrimePi[n] + 1}, While[ JacobiSymbol[n, Prime[k]] == 1, k++ ]; Prime[k]]; NestList[f, 2, 56] (* _Robert G. Wilson v_, Mar 16 2004 *)
%Y A092581 Cf. A034794.
%K A092581 nonn
%O A092581 1,1
%A A092581 _Gary W. Adamson_, Feb 29 2004
%E A092581 More terms from _Robert G. Wilson v_, Mar 16 2004
%E A092581 a(17) corrected by _T. D. Noe_, Aug 28 2007