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 A141948 #13 Jan 16 2023 12:03:34
%S A141948 109,163,271,379,433,487,541,757,811,919,1297,1459,1567,1621,1783,
%T A141948 1999,2053,2161,2269,2377,2539,2593,2647,2917,2971,3079,3187,3457,
%U A141948 3511,3673,3727,3889,3943,4051,4159,4483,4591,4861,4969,5023,5077,5347,5563,5779
%N A141948 Primes congruent to 1 mod 27.
%H A141948 Vincenzo Librandi, <a href="/A141948/b141948.txt">Table of n, a(n) for n = 1..1000</a>
%F A141948 a(n) ~ 18n log n. - _Charles R Greathouse IV_, Jul 02 2016
%t A141948 Select[Prime[Range[800]], MemberQ[{1}, Mod[#, 27]] &] (* _Vincenzo Librandi_, Aug 16 2012 *)
%t A141948 Select[Range[1,6000,27],PrimeQ] (* _Harvey P. Dale_, Jan 16 2023 *)
%o A141948 (Magma) [p: p in PrimesUpTo(7000) | p mod 27 eq 1 ]; // _Vincenzo Librandi_, Aug 16 2012
%o A141948 (PARI) is(n)=isprime(n) && n%27==1 \\ _Charles R Greathouse IV_, Jul 02 2016
%Y A141948 Cf. A000040.
%K A141948 nonn,easy
%O A141948 1,1
%A A141948 _N. J. A. Sloane_, Jul 11 2008