Where m is the largest odd factor of n, I am trying to prove that $$\sigma(n)\equiv d(m)\mod{2}$$
Any help is appreciated!
Where m is the largest odd factor of n, I am trying to prove that $$\sigma(n)\equiv d(m)\mod{2}$$
Any help is appreciated!
Copyright © 2021 JogjaFile Inc.
I presume $\sigma(n)$ is the sum of the divisors of $n$. Then $\sigma(n)\equiv\sigma(m)\pmod2$ as one can ignore even divisors of $n$. For odd $m$, $\sigma(m)\equiv d(m)\pmod2$ as all divisors of $m$ are odd.