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 A020456 #17 Jun 30 2025 16:01:12
%S A020456 11,181,811,881,1181,1811,8111,18181,81181,88811,1111181,1181881,
%T A020456 1881181,1881811,1881881,8118181,8181881,8188111,8188181,8818811,
%U A020456 8881111,8881811,11818181,11881811,11888111,18111881,18118811,18181181,18811181,18888811
%N A020456 Primes that contain digits 1 and 8 only.
%H A020456 Jason Bard, <a href="/A020456/b020456.txt">Table of n, a(n) for n = 1..10000</a> (first 1000 terms from Vincenzo Librandi)
%t A020456 Flatten[Table[Select[FromDigits/@Tuples[{1,8},n],PrimeQ],{n,8}]] (* _Vincenzo Librandi_, Jul 27 2012 *)
%o A020456 (Magma) [p: p in PrimesUpTo(18888811) | Set(Intseq(p)) subset [1, 8]]; // _Vincenzo Librandi_, Jul 27 2012
%K A020456 nonn,base
%O A020456 1,1
%A A020456 _David W. Wilson_