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 A038905 #11 Jul 08 2025 22:28:24 %S A038905 2,3,5,11,23,31,41,43,79,83,97,101,109,113,127,139,149,151,157,167, %T A038905 173,179,193,199,223,233,239,251,257,263,271,281,293,317,331,347,349, %U A038905 367,373,383,397,421,463,487,491 %N A038905 31 is a square mod p. %C A038905 Also, only entries p=1 (mod 4) of the sequence are squares mod 31 (from the quadratic reciprocity law). - _Lekraj Beedassy_, Jul 21 2004 %H A038905 Vincenzo Librandi, <a href="/A038905/b038905.txt">Table of n, a(n) for n = 1..1000</a> %t A038905 Select[Prime[Range[100]], JacobiSymbol[31, #] != -1 &] (* _Vincenzo Librandi_, Sep 07 2012 *) %K A038905 nonn %O A038905 1,1 %A A038905 _N. J. A. Sloane_