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A090151
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Primes of the form identical digits preceded by a 3.
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2
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3, 31, 37, 311, 311111, 31111111111, 311111111111, 377777777777, 31111111111111, 377777777777777777, 31111111111111111111111111111111111, 311111111111111111111111111111111111111111111111
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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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Select[ FromDigits /@ Flatten[ Table[ PadRight[{3}, i, # ] & /@ {1, 2, 3, 4, 5, 6, 7, 8, 9}, {i, 2, 24}], 1], PrimeQ[ # ] &]
Select[Union[Flatten[Table[FromDigits[PadRight[{3}, n, c]], {n, 1000}, {c, {1, 7}}]]], PrimeQ] (* Harvey P. Dale, Oct 03 2022 *)
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PROG
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(Python)
from sympy import isprime
def afind(terms):
print(3, end=", ")
digits, n = 1, 1
while n < terms:
for id in "17":
t = int('3' + id*digits)
if isprime(t): print(t, end=", "); n += 1
digits += 1
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CROSSREFS
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KEYWORD
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nonn,base
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AUTHOR
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STATUS
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approved
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