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%I #12 Sep 08 2022 08:44:45
%S 7,787,877,887,7877,8887,78787,78877,78887,87877,87887,777787,777877,
%T 778777,787777,878777,888887,7778777,7788787,7877777,7878877,7878887,
%U 7888877,8787887,8788777,8877787,8887777,77778887,77787887,77877887
%N Primes that contain digits 7 and 8 only.
%H Vincenzo Librandi, <a href="/A020470/b020470.txt">Table of n, a(n) for n = 1..1000</a>
%t Flatten[Table[Select[FromDigits/@Tuples[{7,8},n],PrimeQ],{n,8}]] (* _Vincenzo Librandi_, Jul 28 2012 *)
%o (Magma) [p: p in PrimesUpTo(77877887) | Set(Intseq(p)) subset [7,8]]; // _Vincenzo Librandi_, Jul 28 2012
%K nonn,base
%O 1,1
%A _David W. Wilson_
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