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 A103521 #2 Oct 19 2017 03:14:39 %S A103521 3,7,13,19,31,43,61,67,79,103,127,151,211,241,271,331,421,463,631,661, %T A103521 691,751,811,1051,1171,1321,1471,1531,1621,1741,2311,2731,2971,3571, %U A103521 3631,4621,4831,4951,5281,6091,6301,6361,7351,8191,9241,9661,9871 %N A103521 Primes which have fewer primitive roots than any larger prime. %Y A103521 Cf. A103203. %K A103521 nonn %O A103521 1,1 %A A103521 _Don Reble_, Mar 21 2005