OFFSET
1,2
COMMENTS
The exponential version of A002093.
LINKS
Amiram Eldar, Table of n, a(n) for n = 1..1000
EXAMPLE
The first 10 values of esigma(k) for k = 1 to 10 are 1, 2, 3, 6, 5, 6, 7, 10, 12, 10. The record values are reached for 1, 2, 3, 4, 7, 8, 9.
MATHEMATICA
f[p_, e_] := DivisorSum[e, p^# &]; esigma[1] = 1; esigma[n_] := Times @@ f @@@ FactorInteger[n]; s = {}; em = 0; Do[e = esigma[n]; If[e > em, em = e; AppendTo[s, n]], {n, 1, 3000}]; s
CROSSREFS
KEYWORD
nonn
AUTHOR
Amiram Eldar, Oct 04 2019
STATUS
approved