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A218406 Numbers k for which sigma(k)/k - 1/5 is an integer. 5
5, 420, 7440, 8190, 18600, 121920, 131040, 95472000, 102136320, 197308800, 433305600, 503255040, 71271827200, 91967616000, 128848035840, 190066406400, 287879454720, 354560976000, 799959888000, 2061580369920, 2208930048000, 100368143884800, 341546502528000 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
COMMENTS
a(15) > 10^11. - Donovan Johnson, Oct 31 2012
a(20) > 10^12. - Giovanni Resta, Nov 04 2012
Note that there are no terms here with abundancy 11/5 (k=2). - Michel Marcus, Jun 26 2013
LINKS
CROSSREFS
Sequence in context: A201887 A365370 A301309 * A217939 A147684 A199090
KEYWORD
nonn
AUTHOR
Zdenek Cervenka, Oct 28 2012
EXTENSIONS
a(8)-a(14) from Donovan Johnson, Oct 31 2012
a(15)-a(19) from Giovanni Resta, Nov 04 2012
More terms from Michel Marcus, Jun 26 2013
STATUS
approved

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Last modified February 28 14:09 EST 2024. Contains 370400 sequences. (Running on oeis4.)