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 A069678 #15 Jan 26 2023 15:08:04
%S A069678 2,3,5,7,11,13,17,19,23,29,31,37,41,43,47,53,59,61,67,71,73,79,83,89,
%T A069678 97,131,137,139,233,239,331,337,431,433,439,631,733,739,839,937,2333,
%U A069678 2339,3331,4337,4339,5333,6337,7331,7333,9337,13331,13337,13339,23333,23339
%N A069678 Primes with either no internal digits or all internal digits are 3.
%H A069678 Harvey P. Dale, <a href="/A069678/b069678.txt">Table of n, a(n) for n = 1..267</a>
%t A069678 Join[Prime[Range[25]],Select[Flatten[Table[10FromDigits[PadRight[{n},k,3]]+d,{n,9},{d,{1,3,7,9}},{k,2,5}]],PrimeQ]]//Sort (* _Harvey P. Dale_, Aug 08 2020 *)
%Y A069678 Cf. A069675, A069676, A069677, A069679, A069680, A069681, A069682, A069683, A069684.
%K A069678 nonn,base
%O A069678 1,1
%A A069678 _Amarnath Murthy_, Apr 06 2002
%E A069678 Offset corrected and name changed by _Arkadiusz Wesolowski_, Sep 07 2011