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Search: id:A104484
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| A104484 |
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Number of distinct prime divisors of 33...331 (with n 3s). |
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+0
5
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| 1, 1, 1, 1, 1, 1, 1, 2, 2, 2, 3, 3, 4, 2, 2, 3, 1, 3, 4, 3, 2, 4, 3, 3, 2, 4, 3, 3, 2, 3, 4, 6, 2, 2, 3, 3, 4, 4, 1, 3, 3, 6, 6, 3, 2, 3, 5, 3, 1, 3
(list; graph; listen)
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OFFSET
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0,8
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COMMENT
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Interestingly, the first seven members in this sequence are all primes.
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EXAMPLE
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Number of distinct prime divisors of 31 is 1 (prime).
Number of distinct prime divisors of 331 is 1 (prime).
Number of distinct prime divisors of 3331 is 1 (prime).
Number of distinct prime divisors of 33331 is 1 (prime).
Number of distinct prime divisors of 333331 is 1 (prime).
Number of distinct prime divisors of 3333331 is 1 (prime).
Number of distinct prime divisors of 33333331 is 1 (prime).
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MATHEMATICA
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Table[Length[FactorInteger[(10^(n + 1) - 7)/3]], {n, 1, 50}] (Steinerberger)
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CROSSREFS
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Sequence in context: A139801 A132328 A064822 this_sequence A038809 A078342 A107325
Adjacent sequences: A104481 A104482 A104483 this_sequence A104485 A104486 A104487
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KEYWORD
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nonn
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AUTHOR
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Parthasarathy Nambi (PachaNambi(AT)yahoo.com), Apr 18 2005
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