OFFSET
1,1
COMMENTS
The unitary version of A071927.
LINKS
Amiram Eldar, Table of n, a(n) for n = 1..10000
EXAMPLE
The values of usigma(k)/k are 2.4, 2.285..., 2.181..., 2.057..., 2.054...
MATHEMATICA
usigma[n_] := If[n == 1, 1, Times @@ (1 + Power @@@ FactorInteger[n])]; seq = {}; r = 3; Do[s = usigma[n]/n; If[s > 2 && s < r, AppendTo[seq, n]; r = s], {n, 1, 10000}]; seq
CROSSREFS
KEYWORD
nonn
AUTHOR
Amiram Eldar, Apr 10 2018
STATUS
approved