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Search: id:A147556
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| A147556 |
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Largest prime factor of prime(n)-th repunit number. |
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1
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| 11, 37, 271, 4649, 513239, 265371653, 5363222357, 1111111111111111111, 11111111111111111111111, 77843839397, 57336415063790604359, 2212394296770203368013, 201763709900322803748657942361
(list; graph; listen)
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OFFSET
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1,1
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COMMENT
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The sequence of repunit primes is a subsequence of this sequence.
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EXAMPLE
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Prime(15)=47 and (10^47-1)/9=35121409*316362908763458525001406154038726382279
so a(15)=316362908763458525001406154038726382279.
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CROSSREFS
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Cf. A004022, A147555.
Sequence in context: A003020 A075024 A152094 this_sequence A120833 A034969 A052432
Adjacent sequences: A147553 A147554 A147555 this_sequence A147557 A147558 A147559
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KEYWORD
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nonn
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AUTHOR
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Farideh Firoozbakht (mymontain(AT)yahoo.com), Dec 26 2008
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