*Add n then reverse digits* sequence (1.5 points)
=================================================

Given a positive integer ``n``, a sequence is defined as follows. The
first term is ``0``. Any other term is computed by adding ``n`` to the
previous term and then reversing the digits. Note that this
sequence is **not** increasing.

Write function :py:func:`add_reverse` that takes two positive
integers, ``n`` and ``nmax`` (:py:class:`int`), and computes the
terms of the previous sequence until it finds the first term that is
greater than ``nmax``, which must **not** be included in the sequence. This
function returns a :py:class:`list` in which all these terms are
stored in the order in which they are generated. Examples:
   
   .. literalinclude:: test-add_reverse.txt
      :language: python
      :lines: 3-10

   .. note:: You have more tests in file :download:`test-add_reverse.txt`