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A107689
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Primes with digital product = 3.
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17
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3, 13, 31, 113, 131, 311, 11113, 11131, 11311, 113111, 131111, 311111, 11111131, 11111311, 11113111, 11131111, 111111113, 111111131, 111113111, 131111111, 11111111113, 11111111131, 11113111111, 11131111111, 31111111111
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OFFSET
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1,1
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LINKS
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MATHEMATICA
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Flatten[ Table[ Select[ Sort[ FromDigits /@ Permutations[ Flatten[{3, Table[1, {n}]}]]], PrimeQ[ # ] &], {n, 0, 12}]]
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PROG
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(Python)
from sympy import isprime
def agen():
digits = 0
while True:
for i in range(digits+1):
t = int("1"*(digits-i) + "3" + "1"*i)
if isprime(t): yield t
digits += 1
g = agen()
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CROSSREFS
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Cf. A004022, A107612, A107690, A107691, A107692, A107693, A107694, A107695, A107696, A107697, A107698.
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KEYWORD
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base,nonn
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AUTHOR
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STATUS
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approved
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