  We present a variety of numerical data related to the growth of terms in
aliquot sequences, iterations of the function $s(n) = \sigma(n) - n$. First, we
compute the geometric mean of the ratio $s_k(n)/s_{k-1}(n)$ of $k$th iterates
for $n \leq 2^{37}$ and $k=1,\dots,10.$ Second, we extend the computation of
numbers not in the range of $s(n)$ (called untouchable) by Pollack and
Pomerance to the bound of $2^{40}$ and use these data to compute the geometric
mean of the ratio of consecutive terms limited to terms in the range of $s(n).$
Third, we give an algorithm to compute $k$-untouchable numbers ($k-1$st
iterates of $s(n)$ but not $k$th iterates) along with some numerical data.
Finally, inspired by earlier work of Devitt, we estimate the growth rate of
terms in aliquot sequences using a Markov chain model based on data extracted
from thousands of sequences.
