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 A020470 #17 Jul 04 2025 11:17:51
%S A020470 7,787,877,887,7877,8887,78787,78877,78887,87877,87887,777787,777877,
%T A020470 778777,787777,878777,888887,7778777,7788787,7877777,7878877,7878887,
%U A020470 7888877,8787887,8788777,8877787,8887777,77778887,77787887,77877887
%N A020470 Primes that contain digits 7 and 8 only.
%H A020470 Jason Bard, <a href="/A020470/b020470.txt">Table of n, a(n) for n = 1..10000</a> (first 1000 terms from Vincenzo Librandi)
%t A020470 Flatten[Table[Select[FromDigits/@Tuples[{7,8},n],PrimeQ],{n,8}]] (* _Vincenzo Librandi_, Jul 28 2012 *)
%o A020470 (Magma) [p: p in PrimesUpTo(77877887) | Set(Intseq(p)) subset [7,8]]; // _Vincenzo Librandi_, Jul 28 2012
%K A020470 nonn,base
%O A020470 1,1
%A A020470 _David W. Wilson_