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 A105881 #9 Mar 31 2024 15:03:32 %S A105881 2,7,11,19,23,31,43,47,59,71,79,83,107,127,131,139,163,167,179,191, %T A105881 199,211,223,227,239,251,263,283,311,331,347,359,379,383,419,443,463, %U A105881 467,479,487,503,563,571,587,599,607,631,647,659,691,719,739,743,751,811,823,827 %N A105881 Primes for which -9 is a primitive root. %H A105881 Vincenzo Librandi, <a href="/A105881/b105881.txt">Table of n, a(n) for n = 1..1000</a> %H A105881 <a href="/index/Pri#primes_root">Index entries for primes by primitive root</a> %t A105881 pr=-9; Select[Prime[Range[200]], MultiplicativeOrder[pr, # ] == #-1 &] %K A105881 nonn %O A105881 1,1 %A A105881 _N. J. A. Sloane_, Apr 24 2005