A218409 Numbers k for which sigma(k)/k - 2/7 is an integer.

42, 3472, 56896, 544635, 2056320, 4021920, 4357080, 6420960, 234852352, 1980840960, 19017782784, 21231974400, 60129083392, 962070839296, 47911115564928, 53603154468864, 46152495793603584, 243298521749451168, 8785228837239816192

Offset

1,1

Comments

a(14) > 10^11. - Donovan Johnson, Oct 31 2012

a(15) > 10^12. - Giovanni Resta, Nov 04 2012

Note that there are no terms with abundancy 9/7 or 23/7. - Michel Marcus, Jun 25 2013

Links

Table of n, a(n) for n=1..19.

Crossrefs

Cf. A218428, A218410, A218411, A218412, A218413.

Sequence in context: A377975 A294626 A361370 * A347169 A181193 A227583

Adjacent sequences: A218406 A218407 A218408 * A218410 A218411 A218412

Keyword

nonn,more

Author

Zdenek Cervenka, Oct 28 2012

Extensions

Missing term added and a(9)-a(13) from Donovan Johnson, Oct 31 2012

a(14) from Giovanni Resta, Nov 04 2012

More terms from Michel Marcus, Jun 25 2013

Status

approved