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A073083 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). 0
1, 10, 12, 24, 615, 4066, 7960, 30432, 49260, 133686, 440286, 1201644, 6640812, 126953125, 411106256, 1046704882, 11046706752 (list; graph; refs; listen; history; internal format)
OFFSET

1,2

COMMENTS

Next term, if it exists, is >11*10^5. - Emeric Deutsch (deutsch(AT)duke.poly.edu), Mar 05 2005

EXAMPLE

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.

CROSSREFS

Sequence in context: A087697 A140972 A108901 * A129508 A015728 A080470

Adjacent sequences:  A073080 A073081 A073082 * A073084 A073085 A073086

KEYWORD

nonn

AUTHOR

Benoit Cloitre (benoit7848c(AT)orange.fr), Aug 17 2002

EXTENSIONS

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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Last modified February 16 17:48 EST 2012. Contains 205939 sequences.