

A134639


Conjectured number of numbers k such that sigma(k)/k = n.


3




OFFSET

3,1


COMMENTS

These numbers come from Guy and Flammenkamp. Sequences A000396, A005820, A027687, A046060 and A046061 give the k for which the abundancy sigma(k)/k is 2, 3, 4, 5 and 6, respectively. Sequence A054030 gives the abundancy of each multiperfect number A007691.


REFERENCES

R. K. Guy, Unsolved Problems in Number Theory, 3rd Ed., New York, SpringerVerlag, 2004, Section B2.


LINKS



CROSSREFS



KEYWORD

nonn,more


AUTHOR



STATUS

approved



