Sagar Mandal

collaborators

4 papers

math.GM2025

Divisibility and Sequence Properties of $σ^{+}$ and $φ^{+}$

Sagar Mandal

Inspired by Lehmer's and Deaconescu's conjectures, as well as various analogue problems concerning Euler's totient function $φ (n)$ , Schemmel's totient function $S_{2} (n)$ , Jordan t…

math.GM2025

A Note on Deaconescu's Conjecture

Sagar Mandal

Hasanalizade [1] studied Deaconescu's conjecture for positive composite integer $n$ . A positive composite integer $n \geq 4$ is said to be a Deaconescu number if $S_{2} (n) ∣ ϕ (n) - 1$ .…

math.GM2025

Exploring the Relationships Between the Divisors of Friends of $10$

Sagar Mandal

A solitary number is a positive integer that shares its abundancy index only with itself. $10$ is the smallest positive integer suspected to be solitary, but no proof has been esta…

math.GM2025

A note on solitary numbers

Sagar Mandal

Does $14$ have a friend? Until now, this has been an open question. In this note, we prove that a potential friend $F$ of $14$ is an odd, non-square positive integer. $7$ appears i…

Divisibility and Sequence Properties of σ+ and φ+

A Note on Deaconescu's Conjecture

Exploring the Relationships Between the Divisors of Friends of 10

A note on solitary numbers

Divisibility and Sequence Properties of $σ^{+}$ and $φ^{+}$

Exploring the Relationships Between the Divisors of Friends of $10$