e-Perfect Number
A number is called an
-perfect number
if
, where
is the
sum of the e-Divisors
of
. If
is squarefree,
then
. As a result, if
is
-perfect and
is squarefree with
, then
is
-perfect.
The first few -perfect numbers are 36, 180, 252, 396,
468, ... (Sloane's A054979). There are no odd
-perfect numbers.
The first few primitive
-perfect numbers
are 36, 1800, 2700, 17424, ... (Sloane's A054980).