Consider the sequence of positive integers
defined by
and
.
Graham and Pollak discovered the unexpected fact that
is just the
-th digit in the binary
expansion of
. Fix
. In this note, we
first give two infinite families of similar nonlinear recurrences
such that
indicates the
-th binary digit
of
. Moreover, for all integral
, we establish a
recurrence such that
denotes the
-th digit
of
in the
-ary digital expansion.