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A261182
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Primes that contain only the digits (2, 7, 9).
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2
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2, 7, 29, 79, 97, 227, 229, 277, 727, 797, 929, 977, 997, 2297, 2729, 2777, 2797, 2927, 2999, 7229, 7297, 7727, 7927, 9227, 9277, 9929, 22229, 22277, 22279, 22727, 22777, 27277, 27299, 27779, 27799, 27997, 29297, 29927, 72227, 72229, 72277, 72727, 72797
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OFFSET
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1,1
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COMMENTS
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LINKS
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MATHEMATICA
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Select[Prime[Range[2 10^4]], Complement[IntegerDigits[#], {2, 7, 9}] == {} &]
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PROG
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(Magma) [p: p in PrimesUpTo(2*10^5) | Set(Intseq(p)) subset [2, 7, 9]];
(Python)
from gmpy2 import is_prime
from itertools import product
A261182_list = [int(''.join(d)) for l in range(1, 10) for d in product('279', repeat=l) if is_prime(int(''.join(d)))] # Chai Wah Wu, Aug 11 2015
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CROSSREFS
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Cf. similar sequences listed in A261181.
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KEYWORD
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nonn,easy,base
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AUTHOR
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STATUS
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approved
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