A218410 Numbers k for which sigma(k)/k - 3/7 is an integer.

840, 55860, 1089270, 3666432, 5322240, 8714160, 10281600, 20109600, 21785400, 32104800, 9904204800, 10334134272, 4660073935104, 7322605472000, 11887123248000, 15387946358400, 78599399424000, 516876560449536, 750304684523520, 812193794048000

Offset: 1

Author

Zdenek Cervenka, Oct 28 2012

Keywords

• nonn

Comments

a(13) > 10^11. - Donovan Johnson, Oct 31 2012

a(13) > 10^12. - Giovanni Resta, Nov 04 2012

Note that there are no terms with abundancy 10/7 or 17/7. - Michel Marcus, Jun 25 2013

Crossrefs

Cf. A218428, A218409, A218411, A218412, A218413.

Extensions

a(5)-a(12) from Donovan Johnson, Oct 31 2012

More terms from Michel Marcus, Jun 25 2013