On Exactly $3$-Deficient-Perfect Numbers

Saralee Aursukaree, Prapanpong Pongsriiam

Let $n$ and $k$ be positive integers and $\sigma (n)$ the sum of all positive divisors of $n$. We call $n$ an exactly $k$-deficient-perfect number with deficient divisors $d_1, d_2, \ldo…