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A214705
Primes that contain only the digits (2, 5, 7).
2
2, 5, 7, 227, 257, 277, 557, 577, 727, 757, 2557, 2777, 5227, 5527, 5557, 7577, 7727, 7757, 22277, 22727, 22777, 25577, 27277, 27527, 52727, 52757, 57527, 57557, 57727, 72227, 72277, 72577, 72727, 75227, 75277, 75527, 75557, 75577, 77527, 77557, 222527, 222557
OFFSET
1,1
COMMENTS
The digits are prime numbers.
LINKS
MATHEMATICA
Flatten[Table[Select[FromDigits/@Tuples[{2, 5, 7}, n], PrimeQ], {n, 6}]]
PROG
(Magma) [p: p in PrimesUpTo(100000) | Set(Intseq(p)) subset [2, 5, 7]];
(Python)
from sympy import primerange
def ok(p): return set(str(p)) <= set("257")
def aupto(limit): return [p for p in primerange(2, limit+1) if ok(p)]
print(aupto(222557)) # Michael S. Branicky, Feb 05 2021
CROSSREFS
Subsequence of A019546.
Sequence in context: A058854 A006275 A042673 * A252283 A007571 A350590
KEYWORD
nonn,base,easy
AUTHOR
Vincenzo Librandi, Jul 28 2012
STATUS
approved