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A218407 Numbers k for which sigma(k)/k - 2/5 is an integer. 5
30, 140, 2480, 6200, 40640, 297600, 997920, 64995840, 167751680, 1502582400, 42949345280, 183196016640, 687193456640, 1447428787200, 63870637017600, 326676430080000, 20797363851264000, 24871926476966400, 42981218625945600, 404918548479244800 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
COMMENTS
a(12) > 10^11. - Donovan Johnson, Oct 31 2012
a(14) > 10^12. - Giovanni Resta, Nov 04 2012
Note that there are no terms here with abundancy 7/5 (k=1). - Michel Marcus, Jun 26 2013
LINKS
CROSSREFS
Sequence in context: A158462 A064495 A267904 * A347222 A229450 A124958
KEYWORD
nonn
AUTHOR
Zdenek Cervenka, Oct 28 2012
EXTENSIONS
a(8)-a(11) from Donovan Johnson, Oct 31 2012
a(12)-a(13) from Giovanni Resta, Nov 04 2012
More terms from Michel Marcus, Jun 26 2013
STATUS
approved

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Last modified May 19 14:45 EDT 2024. Contains 372698 sequences. (Running on oeis4.)