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 A142748 #11 Sep 08 2022 08:45:37
%S A142748 139,257,1201,1319,2027,2381,2617,2971,3089,3797,5449,6983,7219,7573,
%T A142748 7691,7927,8753,9343,9461,9697,10169,11113,11467,11821,11939,12647,
%U A142748 13001,13591,13709,14653,14771,15361,16069,16187,17839,17957,18311,19373,19609,19727
%N A142748 Primes congruent to 21 mod 59.
%H A142748 Vincenzo Librandi, <a href="/A142748/b142748.txt">Table of n, a(n) for n = 1..1000</a>
%t A142748 Select[Range[21, 30000, 118], PrimeQ] (* _Vladimir Joseph Stephan Orlovsky_, Jul 15 2011 *)
%t A142748 Select[Prime[Range[2400]], MemberQ[{21}, Mod[#, 59]] &] (* _Vincenzo Librandi_, Sep 03 2012 *)
%o A142748 (Magma) [p: p in PrimesUpTo(20000) | p mod 59 eq 21 ]; // _Vincenzo Librandi_, Sep 03 2012
%Y A142748 Cf. A000040, A142742, A142744, A142746.
%K A142748 nonn,easy
%O A142748 1,1
%A A142748 _N. J. A. Sloane_, Jul 11 2008