DOI: 10.4153/s0008439526102513 ISSN: 0008-4395
Disproofs of two conjectures concerning nondeficient numbers
John M. Campbell Abstract
A positive integer
n
is said to be
nondeficient
if
σ
(
n
)
≥
2
n
$\sigma (n) \geq 2n$
sigma left parenthesis n right parenthesis greater than or equals 2 n
. Letting the positive divisors of an integer
n
>
1
$n> 1$
n greater than 1
be written as
1
=
d
0
<
d
1
<
⋯
<
d
k
<
d
k
+
1
=
n
$1 = d_0 < d_1 < \cdots < d_k < d_{k+1} = n$
1 equals d 0 less than d 1 less than midline horizontal ellipsis less than d Subscript k Baseline less than d Subscript k plus 1 Baseline equals n
, and letting
S
$\mathcal {S}$
script upper S
denote a set of integers, if there exist values
λ
j
∈
S
$\lambda _j \in \mathcal {S}$
lamda Subscript j Baseline element of script upper S
such that
1
+
∑
j
=
1
k
λ
j
d
j
=
n
$1 + \sum _{j=1}^{k} \lambda _j d_j = n$
1 plus sigma summation Underscript j equals 1 Overscript k Endscripts lamda Subscript j Baseline d Subscript j Baseline equals n
, then
n
is said to be an
S
$\mathcal {S}$
script upper S
-perfect number
. Ross, in 2024, introduced the study of
S
$\mathcal {S}$
script upper S
-perfect numbers and concluded with two conjectures that each concern both
{
−
1
,
1
}
$\{ -1, 1 \}$
StartSet negative 1 comma 1 EndSet
-perfect numbers and nondeficient numbers. We disprove both of these conjectures.