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 A118818 #15 Oct 11 2021 04:37:18 %S A118818 223,379,463,631,691,883,907,1051,1423,1447,1543,1723,1747,1783,1987, %T A118818 2143,2179,2347,2467,2591,2767,3259,3307,3511,3631,3691,3739,3823, %U A118818 3907,4219,4447,4507,4519,4639,4987,5023,5107,5119,5347,5683,5923 %N A118818 Primes p for which there are more primitive roots below p/2 than above p/2. %C A118818 All terms are of the form 4*m + 3 (see A172480 and A172490). - _Emmanuel Vantieghem_, Nov 07 2016 %H A118818 Amiram Eldar, <a href="/A118818/b118818.txt">Table of n, a(n) for n = 1..1000</a> %e A118818 223 is a term because it has 38 primitive roots below 111.5, but 34 above 111.5. %t A118818 q[n_] := PrimeQ[n] && Length[(p = PrimitiveRootList[n])] > 2*Count[p, _?(# > n/2 &)]; Select[4*Range[0, 1500] + 3, q] (* _Amiram Eldar_, Oct 11 2021 *) %Y A118818 Cf. A128859, A172480, A172490. %K A118818 nonn %O A118818 1,1 %A A118818 _Don Reble_, Apr 20 2007