  We show that for all given $n,t,w \in \{1,2,...\}$ with $n<2^w$, an array of
$n$ entries of $w$ bits each can be represented on a word RAM with a word
length of $w$ bits in at most $nw+\lceil n(t/(2 w))^t\rceil$ bits of
uninitialized memory to support constant-time initialization of the whole array
and $O(t)$-time reading and writing of individual array entries. At one end of
this tradeoff, we achieve initialization and access (i.e., reading and writing)
in constant time with $nw+\lceil n/w^t\rceil$ bits for arbitrary fixed $t$, to
be compared with $nw+\Theta(n)$ bits for the best previous solution, and at the
opposite end, still with constant-time initialization, we support $O(\log
n)$-time access with just $nw+1$ bits, which is optimal for arbitrary access
times if the initialization executes fewer than $n$ steps.
