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Primes that contain digits 3 and 8 only.
8

%I #15 Sep 08 2022 08:44:45

%S 3,83,383,883,3833,38333,38833,83383,83833,88883,333383,338383,383833,

%T 3333383,3383383,3833833,3838333,3838883,3883333,3888383,8338333,

%U 8388833,8838383,8838833,8838883,8883883,38383883,83333333,83883883,88838333

%N Primes that contain digits 3 and 8 only.

%H Vincenzo Librandi, <a href="/A020464/b020464.txt">Table of n, a(n) for n = 1..1000</a>

%t Flatten[Table[Select[FromDigits/@Tuples[{3,8},n],PrimeQ],{n,8}]] (* _Vincenzo Librandi_, Jul 27 2012 *)

%t Select[Flatten[Table[10#+3&/@(FromDigits/@Tuples[{3,8},n]),{n,0,7}]], PrimeQ] (* _Harvey P. Dale_, Jan 06 2019 *)

%o (Magma) [p: p in PrimesUpTo(88838333) | Set(Intseq(p)) subset [3,8]]; // _Vincenzo Librandi_, Jul 27 2012

%K nonn,base

%O 1,1

%A _David W. Wilson_