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 A020452 #33 Sep 08 2022 08:44:45
%S A020452 11,41,4111,4441,11411,14411,41141,41411,44111,1114111,1144141,
%T A020452 1144441,1411141,1411411,1441411,1444111,1444411,1444441,4141441,
%U A020452 4414411,4441111,4441441,11111141,11141111,11141441,11441141,11441411,14111441,14141411
%N A020452 Primes that contain digits 1 and 4 only.
%H A020452 Alois P. Heinz, <a href="/A020452/b020452.txt">Table of n, a(n) for n = 1..20000</a> (first 1000 terms from Vincenzo Librandi)
%H A020452 James Maynard and Brady Haran, <a href="https://www.youtube.com/watch?v=eeoBCS7IEqs">Primes without a 7</a>, Numberphile video (2019).
%t A020452 Flatten[Table[Select[FromDigits/@Tuples[{1,4},n],PrimeQ],{n,8}]] (* _Vincenzo Librandi_, Jul 27 2012 *)
%o A020452 (Magma) [p: p in PrimesUpTo(14141411) | Set(Intseq(p)) subset [1,4]]; // _Bruno Berselli_, Jul 27 2012
%o A020452 (Python)
%o A020452 from sympy import primerange
%o A020452 def checkd(a, c):
%o A020452 b = set(int(i) for i in set(str(a)))
%o A020452 return b.issubset(c)
%o A020452 for n in primerange(2, 2000000):
%o A020452 if checkd(n, [1, 4]):
%o A020452 print(n)
%o A020452 # _Abhiram R Devesh_, May 08 2015
%Y A020452 Cf. A032822.
%K A020452 nonn,base
%O A020452 1,1
%A A020452 _David W. Wilson_