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Search: id:A079814
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| A079814 |
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Odd integers such that Euler totient function phi(n)/n < 6/pi^2. |
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+0
1
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| 15, 21, 33, 45, 63, 75, 99, 105, 135, 147, 165, 189, 195, 225, 231, 255, 273, 285, 297, 315, 345, 357, 363, 375, 399, 405, 429, 435, 441, 465, 483, 495, 525, 555, 561, 567, 585, 609, 615, 627, 645, 651, 663, 675, 693, 705, 735, 741, 759, 765, 777, 795, 819
(list; graph; listen)
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OFFSET
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1,1
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COMMENT
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Since, as Euler proved, the random chance of two integers' not having a common prime factor is 6/pi^2, these are the odd integers that share common factors with an above average fraction of integers. Is it known, or can it be calculated, what portion of odd integers satisfy this condition? (All even numbers qualify; for all multiples of 2, phi(n)/n <= .5.)
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EXAMPLE
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phi (33)/33 = 20/33 or .6060606...; 6/pi^2 is .6079271....
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CROSSREFS
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See A000010 (Euler totient function phi(n)).
Sequence in context: A099610 A127329 A043326 this_sequence A090999 A123912 A128279
Adjacent sequences: A079811 A079812 A079813 this_sequence A079815 A079816 A079817
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KEYWORD
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easy,nonn
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AUTHOR
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Matthew Vandermast (ghodges14(AT)comcast.net), Feb 19 2003
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