A normal random walk use step $+1$ or $-1$ for some probability with barrier at $+n$, $-n$.
Assume a random walk with step $-1,-2,...-k$ and $+1,+2,...+k$ with absorbing barriers at $+n$ and $-n$ (the probability of steps are uniform $1/k$).
What is $P(k, n)$ = Probability absorption at $n$ with $k$ steps, starting with the + steps. EX: $P(3,2) = 9/11$.