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Primes that contain only the digits (5, 6, 7).
2

%I #13 Sep 08 2022 08:46:13

%S 5,7,67,557,577,677,757,5557,5657,6577,7577,7757,55667,56767,57557,

%T 57667,65557,65657,65677,65777,67567,67577,67757,67777,75557,75577,

%U 75767,76667,76757,76777,77557,555557,555677,555767,557567,565567,565667,566557,566567

%N Primes that contain only the digits (5, 6, 7).

%C A020467 and A020469 are subsequences.

%H Alois P. Heinz, <a href="/A260829/b260829.txt">Table of n, a(n) for n = 1..10000</a>

%H James Maynard and Brady Haran, <a href="https://www.youtube.com/watch?v=eeoBCS7IEqs">Primes without a 7</a>, Numberphile video (2019)

%t Select[Prime[Range[2 10^5]], Complement[IntegerDigits[#], {5, 6, 7}] == {} &]

%o (Magma) [p: p in PrimesUpTo(2*10^6) | Set(Intseq(p)) subset [5,6,7]];

%Y Cf. similar sequences listed in A260827.

%Y Cf. A020467, A020469.

%K nonn,easy,base

%O 1,1

%A _Vincenzo Librandi_, Aug 02 2015