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A260828 Primes having only {1, 5, 7} as digits.

%I A260828 #23 Jul 20 2025 18:02:12
%S A260828 5,7,11,17,71,151,157,557,571,577,751,757,1117,1151,1171,1511,1571,
%T A260828 1777,5171,5557,5711,5717,7151,7177,7517,7577,7717,7757,11117,11171,
%U A260828 11177,11551,11717,11777,15511,15551,17117,17551,51151,51157,51511,51517,51551,51577
%N A260828 Primes having only {1, 5, 7} as digits.
%H A260828 Alois P. Heinz, <a href="/A260828/b260828.txt">Table of n, a(n) for n = 1..10000</a>
%H A260828 James Maynard and Brady Haran, <a href="https://www.youtube.com/watch?v=eeoBCS7IEqs">Primes without a 7</a>, Numberphile video (2019)
%H A260828 <a href="/index/Pri#PrimesWithDigits">Index to entries for primes with digits in a given set</a>
%t A260828 Select[Prime[Range[2 10^4]], Complement[IntegerDigits[#], {1, 5, 7}] == {} &]
%o A260828 (Magma) [p: p in PrimesUpTo(2*10^5) | Set(Intseq(p)) subset [1,5,7]];
%o A260828 (Python)
%o A260828 from sympy import isprime
%o A260828 from sympy.utilities.iterables import multiset_permutations
%o A260828 def aupton(terms):
%o A260828   n, digits, alst = 0, 1, []
%o A260828   while len(alst) < terms:
%o A260828     mpstr = "".join(d*digits for d in "157")
%o A260828     for mp in multiset_permutations(mpstr, digits):
%o A260828       t = int("".join(mp))
%o A260828       if isprime(t): alst.append(t)
%o A260828       if len(alst) == terms: break
%o A260828     else: digits += 1
%o A260828   return alst
%o A260828 print(aupton(44)) # _Michael S. Branicky_, May 07 2021
%Y A260828 Subsequence of A030096. A020453, A020455 and A020467 are subsequences.
%Y A260828 Cf. similar sequences listed in A260827.
%Y A260828 Cf. A000040.
%K A260828 nonn,easy,base
%O A260828 1,1
%A A260828 _Vincenzo Librandi_, Aug 02 2015