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 A142218 #18 May 16 2024 15:44:15
%S A142218 103,349,431,677,1087,1579,1907,2153,2399,3137,3301,3547,3793,5023,
%T A142218 5351,5843,6007,6089,6581,6827,6991,7237,8221,8467,8713,9041,9533,
%U A142218 9697,10271,11173,12157,12239,13469,13633,13879,14207,14699,15601,15683,16339,16421
%N A142218 Primes congruent to 21 mod 41.
%H A142218 Vincenzo Librandi, <a href="/A142218/b142218.txt">Table of n, a(n) for n = 1..1000</a>
%F A142218 a(n) ~ 40n log n. - _Charles R Greathouse IV_, Jul 03 2016
%t A142218 Select[Range[21,30000,41],PrimeQ] (* _Vladimir Joseph Stephan Orlovsky_, Jun 03 2011 *)
%t A142218 Select[Prime[Range[5000]],MemberQ[{21},Mod[#,41]]&] (* _Vincenzo Librandi_, Aug 23 2012 *)
%o A142218 (Magma) [p: p in PrimesUpTo(17000) | p mod 41 eq 21 ]; // _Vincenzo Librandi_, Aug 23 2012
%o A142218 (PARI) is(n)=isprime(n) && n%41==21 \\ _Charles R Greathouse IV_, Jul 03 2016
%Y A142218 Cf. A000040, A142216, A142217.
%K A142218 nonn,easy
%O A142218 1,1
%A A142218 _N. J. A. Sloane_, Jul 11 2008