login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

A218413
Numbers k for which sigma(k)/k - 6/7 is an integer.
5
168, 11172, 217854, 228480, 446880, 220093440, 5228496000, 10805558400, 14091504577920, 583455456460800, 2583890834482298880, 5510058011880428160, 224050000769667072000, 1022756201136515973120, 1314073124731389718080, 2661277331943365990400
OFFSET
1,1
COMMENTS
a(9) > 10^11. - Donovan Johnson, Oct 31 2012
a(9) > 10^12. - Giovanni Resta, Nov 04 2012
Note that there are no terms with abundancy 13/7. - Michel Marcus, Jun 25 2013
CROSSREFS
KEYWORD
nonn
AUTHOR
Zdenek Cervenka, Oct 28 2012
EXTENSIONS
a(6)-a(8) from Donovan Johnson, Oct 31 2012
More terms from Michel Marcus, Jun 25 2013
STATUS
approved