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Search: id:A104889
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| A104889 |
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Number of distinct prime divisors of 44...447 (with n 4s). |
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+0
3
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| 1, 2, 1, 2, 3, 2, 2, 4, 1, 3, 2, 3, 2, 2, 2, 2, 3, 3, 1, 5, 4, 4, 4, 7, 1, 4, 2, 5, 3, 3, 3, 3, 3, 6, 4, 5, 3, 2, 3, 5
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OFFSET
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0,2
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COMMENT
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Also number of distinct prime factors of (10^(n + 1) - 1)*4/9 + 3. - Stefan Steinerberger (stefan.steinerberger(AT)gmail.com), Feb 21 2006
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EXAMPLE
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Number of distinct prime divisors of 47 is 1 (prime).
Number of distinct prime divisors of 447 is 2.
Number of distinct prime divisors of 4447 is 1 (prime).
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MATHEMATICA
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Table[Length[FactorInteger[(10^(n + 1) - 1)*4/9 + 3]], {n, 1, 40}] - Stefan Steinerberger (stefan.steinerberger(AT)gmail.com), Feb 21 2006
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CROSSREFS
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Cf. A104564.
Adjacent sequences: A104886 A104887 A104888 this_sequence A104890 A104891 A104892
Sequence in context: A098357 A058071 A094572 this_sequence A117910 A029267 A111725
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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 24 2005
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EXTENSIONS
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More terms from Stefan Steinerberger (stefan.steinerberger(AT)gmail.com), Feb 21 2006
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