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Search: id:A073083
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| A073083 |
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Numbers n such that sum k/d(k) is an integer, where d(k) is the k-th divisor of n (the divisors of n are in decreasing order). |
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+0
1
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| 1, 10, 12, 24, 615, 4066, 7960, 30432, 49260, 133686, 440286, 1201644, 6640812, 126953125, 411106256, 1046704882, 11046706752
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OFFSET
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1,2
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COMMENT
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Next term, if it exists, is >11*10^5. - Emeric Deutsch (deutsch(AT)duke.poly.edu), Mar 05 2005
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EXAMPLE
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The divisors of 615 are [615,205,123,41,15,5,3,1] and 1/615+2/205+3/123+4/41+5/15+6/5+7/3+8/1 = 12 is an integer hence 615 is in the sequence.
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CROSSREFS
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Sequence in context: A087697 A140972 A108901 this_sequence A129508 A015728 A080470
Adjacent sequences: A073080 A073081 A073082 this_sequence A073084 A073085 A073086
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KEYWORD
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nonn
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AUTHOR
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Benoit Cloitre (benoit7848c(AT)orange.fr), Aug 17 2002
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EXTENSIONS
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More terms from Emeric Deutsch (deutsch(AT)duke.poly.edu), Mar 05 2005
a(12) - a(18) from Lambert Klasen (lambert.klasen(AT)gmx.net), Jul 15 2005
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