Don't know if this really helps, but this is a starting point (I may have made some mistakes, please carefully check the last formula, if you have computed it for small values use it). Let $F(X)=\frac{1}{1-X}=\sum_{k=0}^{\infty}X^k$. We denote $D$ the operator on power series of derivation by $X$ and $XD$ the operator of derivation and multiplication by $X$. Then :
$$D^{r-1}F(X)=\sum_{k=0}^{\infty}(r-1)!\binom{k}{r-1}X^{k-r+1} =\sum_{k=0}^{\infty}(r-1)!\binom{k+r-1}{r-1}X^k$$
Finally :
$$(XD)^nD^{r-1}F(X)=\sum_{k=0}^{\infty}(r-1)!\binom{k+r-1}{r-1}k^nX^k $$
Ok so now $G_{n,r}(X):=(XD)^nD^{r-1}F(X)$ is a regular rational fraction which you can compute (by tedious computations that are easily handled by a computer). The convergence radius of $G_{n,r}$ is clearly $1$, thus we can evaluate $G_{n,r}$ in $1-p$ which gives us the sum you want up to $(r-1)!$
For instance :
$$G_{1,1}(X)=\frac{X}{(1-X)^2}\text{ thus the number you are looking for is } \frac{1-p}{p^2}$$
$$G_{2,1}(X)=\frac{X}{(1-X)^2}+\frac{2X}{(1-X)^3}\text{ thus...}$$
$$G_{3,1}(X)=\frac{X}{(1-X)^2}+\frac{6X}{(1-X)^3}+\frac{6X^3}{(1-X)^4}\text{ thus...}$$
To have a finite sum formula out of this, I suggest you use the following two results :
$D^{r-1}F(X)=(r-1)!\frac{1}{(1-X)^r}$ (easy)
if you are given a power series $f(X)$ and you want to know $(XD)^nf(X)$ there is a nice formula for $n\geq 1$
$$(XD)^nf(X)=\sum_{\ell=1}^ns(\ell,n)X^{\ell}D^{\ell}f(X) $$
where $s(k,n)$ are Stierling numbers of the second kind (it is not hard to prove: induction). So that :
$$G_{n,r}(X)=\sum_{\ell=1}^ns(\ell,n)X^{\ell}D^{\ell+r-1}f(X) $$
$$G_{n,r}(X)=\sum_{\ell=1}^ns(\ell,n)X^{\ell}\frac{(\ell+r-1)!}{(1-X)^{\ell+r}}$$
So that the number you are looking for is :
$$\sum_{\ell=1}^ns(\ell,n)\frac{(\ell+r-1)!(1-p)^{\ell}}{(r-1)!p^{\ell+r}} $$