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 A280930 #12 Jan 01 2018 19:50:13 %S A280930 2,3,5,11,13,19,23,29,37,41,47,53,59,61,67,71,73,83,97,101,103,107, %T A280930 109,131,139,149,151,157,163,167,173,179,181,191,193,197,211,227,229, %U A280930 239,241,251,263,269,271,277,293,307,311,313,317,337,347,349,359,367,373 %N A280930 Primes for which 3 is not the smallest primitive root. %H A280930 Vincenzo Librandi, <a href="/A280930/b280930.txt">Table of n, a(n) for n = 1..7700</a> %t A280930 Select[Prime[Range[1, 100]], PrimitiveRoot[#] =!= 3 &] %t A280930 Select[Prime[Range[100]],PrimitiveRoot[#,1]!=3&] (* _Harvey P. Dale_, Jan 01 2018 *) %Y A280930 Complement of A001123. %K A280930 nonn %O A280930 1,1 %A A280930 _Vincenzo Librandi_, Jan 11 2017