Probably this is easy, but we would like to see it on paper.
Let $p$ be prime and $D,g,n$ positive integers.
Let $A=g^n \bmod p^D$.
Let $\log(p,a,D)$ be the p-adic logarithm with precision $D$.
In pari/gp notation: $\log(p,a,D)=$log(a+O(p^D))
.
$\log(p,a,D)$ is efficiently computable.
Define $dlog(p,g,A,D)=\frac{\log(p,A,D)}{\log(p,g,D)}$.
Is is true that $dlog(p,g,A,D) \bmod{p^{D-1}} = n \bmod{p^{D-1}}$?
We tested hundreds of large tuples for experimental support.
This might have some cryptography application for discrete logarithms modulo prime powers.