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 A059666 #10 Sep 08 2022 08:45:03
%S A059666 3943,11287,20143,23599,25759,26407,29863,32833,33751,38287,39367,
%T A059666 39799,46441,47737,47791,59887,62047,63127,68311,73063,79273,82351,
%U A059666 84457,84673,88129,90289,91639,93529,94447,101089,104761,107839,140617,144073,146449,150607
%N A059666 Primes p such that x^54 = 2 has no solution mod p, but x^18 = 2 has a solution mod p.
%H A059666 Vincenzo Librandi, <a href="/A059666/b059666.txt">Table of n, a(n) for n = 1..49</a>
%t A059666 Select[Prime[Range[PrimePi[200000]]],!MemberQ[PowerMod[Range[#],54,#],Mod[2,#]] && MemberQ[PowerMod[Range[#],18,#],Mod[2,#]]&] (* _Vincenzo Librandi_, Sep 21 2013 *)
%o A059666 (Magma) [p: p in PrimesUpTo(40000) | not exists{x: x in ResidueClassRing(p) | x^54 eq 2} and exists{x: x in ResidueClassRing(p) | x^18 eq 2}]; // _Vincenzo Librandi_, Sep 21 2012
%Y A059666 A000040, A049550, A040993.
%K A059666 nonn,easy
%O A059666 1,1
%A A059666 _Klaus Brockhaus_, Feb 05 2001
%E A059666 More terms from _Vincenzo Librandi_, Sep 21 2013