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 A020461 #17 Jul 01 2025 08:29:05
%S A020461 3,43,433,443,3343,3433,33343,333433,334333,343333,343433,444343,
%T A020461 444443,3333433,3343343,3343433,3344333,3344443,3433333,3434443,
%U A020461 3443443,3444443,4344443,4433333,4434343,4443433,34333333,34434343,34444343,43444433
%N A020461 Primes that contain digits 3 and 4 only.
%H A020461 Jason Bard, <a href="/A020461/b020461.txt">Table of n, a(n) for n = 1..10000</a> (first 1000 terms from Vincenzo Librandi)
%t A020461 Flatten[Table[Select[FromDigits/@Tuples[{3,4},n],PrimeQ],{n,8}]] (* _Vincenzo Librandi_, Jul 27 2012 *)
%o A020461 (Magma) [p: p in PrimesUpTo(43444433) | Set(Intseq(p)) subset [3,4]];
%o A020461 // _Bruno Berselli_, Jul 27 2012
%Y A020461 Cf. A054356.
%K A020461 nonn,base
%O A020461 1,1
%A A020461 _David W. Wilson_