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Search: id:A137413
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| A137413 |
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a(n) = the number of positive integers that are <= n and are coprime to (the sum of the distinct prime divisors of n). |
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+0
1
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| 1, 1, 2, 2, 4, 5, 6, 4, 6, 9, 10, 10, 12, 10, 8, 8, 16, 15, 18, 18, 9
(list; graph; listen)
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OFFSET
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1,3
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LINKS
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Leroy Quet, Home Page (listed in lieu of email address)
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EXAMPLE
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The distinct primes dividing 21 are 3 and 7. 3+7 = 10. The positive integers that are <= 21 and are coprime to 10 are 1,3,7,9,11,13,17,19,21. There are 9 of these; so a(21) = 9.
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CROSSREFS
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Cf. A008472.
Adjacent sequences: A137410 A137411 A137412 this_sequence A137414 A137415 A137416
Sequence in context: A085085 A121600 A126870 this_sequence A010848 A133937 A130498
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KEYWORD
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more,nonn
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AUTHOR
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Leroy Quet Apr 15 2008
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