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A218428 Numbers n for which sigma(n)/n = k+1/7 with integer k. 5
7, 56, 3724, 333312, 939466752, 88884432000, 95088913920, 183694492800, 85621850496000, 120354474240000, 176951824358400, 239555577824640, 268015772344320, 2056513874688000, 9918742759833600, 93442741956748800, 149180517860774400, 230762478968017920 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

a(8) > 10^11. - Donovan Johnson, Oct 31 2012

a(9) > 10^12. - Giovanni Resta, Nov 04 2012

Note that there are no terms here with abundancy 29/7 (k=4). - Michel Marcus, Jun 25 2013

LINKS

Table of n, a(n) for n=1..18.

FORMULA

sigma(n)/n = k+1/7 with integer k.

CROSSREFS

Cf. A218409, A218410, A218411, A218412, A218413.

Sequence in context: A245249 A110830 A304691 * A274721 A180817 A201438

Adjacent sequences:  A218425 A218426 A218427 * A218429 A218430 A218431

KEYWORD

nonn

AUTHOR

Zdenek Cervenka, Oct 28 2012

EXTENSIONS

a(5)-a(7) from Donovan Johnson, Oct 31 2012

a(8) from Giovanni Resta, Nov 04 2012

More terms from Michel Marcus, Jun 25 2013

STATUS

approved

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Last modified October 20 16:07 EDT 2021. Contains 348111 sequences. (Running on oeis4.)