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A107695
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Primes with digital product = 9.
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12
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19, 191, 313, 331, 911, 11119, 111119, 111191, 113131, 131113, 131311, 911111, 1131113, 1131131, 1311131, 1311311, 3111131, 3113111, 11111119, 11111911, 11911111, 111111313, 111111331, 111113113, 111113131, 111131131, 111133111
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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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Union[ Flatten[ Table[ Select[ Sort[ FromDigits /@ Join[ Permutations[ Flatten[{9, Table[1, {n}]}]], Permutations[ Flatten[{3, 3, Table[1, {n - 1}]}]]]], PrimeQ[ # ] & ], {n, 0, 8}]]]
Select[Prime[Range[3 10^6]], Times@@IntegerDigits[#] == 9 &] (* Vincenzo Librandi, Jul 27 2016 *)
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PROG
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(Magma) [p: p in PrimesUpTo(3*10^7) | &*Intseq(p) eq 9]; // Vincenzo Librandi, Jul 27 2016
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CROSSREFS
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Cf. A004022, A107612, A107689, A107690, A107691, A107692, A107693, A107694, 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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