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 A306224 #11 Feb 14 2019 16:15:57 %S A306224 3,5,5,3,11,13,3,5,7,3,7,5,3,11,7,3,5,5,3,11,13,3,5,13,3,11,5,3,7,7,3, %T A306224 5,5,3,19,7,3,5,7,3,13,5,3,7,11,3,5,5,3,7,7,3,5,13,3,11,5,3,11,7,3,5, %U A306224 5,3,7,19,3,5,11,3,7,5,3,7,11,3,5,5,3,11,7,3,5,13,3,7,5 %N A306224 a(n) is the smallest prime p such that -n is not a square mod p. %C A306224 a(n) is the smallest odd prime p such that Kronecker(-n,p) = -1. %C A306224 A companion sequence to A144294. %C A306224 Conjecture: lim sup log(a(n))/log(n) = 0. %F A306224 a(n) = 3 if and only if n == 1 (mod 3). %F A306224 a(n) = 5 if and only if n == 2, 3, 8, 12 (mod 15). %o A306224 (PARI) a(n) = forprime(p=3, , if(kronecker(-n, p)<0, return(p))) %Y A306224 Cf. A144294. %Y A306224 See A306220 for another version. %K A306224 nonn %O A306224 1,1 %A A306224 _Jianing Song_, Jan 30 2019