Math::Series defines a class for simple mathematic series with a recursive
definition such as x_(n+1) = 1 / (x_n + 1). Such a recursive definition is
treated as a sequence whose elements will be added to form a series. You
can refer to the previous sequence element as well as to the current index
in the series. Creation of a Math::Series object is described below in the
paragraph about the constructor.

Math::Series uses Math::Symbolic to parse and modify the recursive
sequence definitions. That means you specify the sequence as a string
which is parsed by Math::Symbolic. Alternatively, you can pass the
constructor a Math::Symbolic tree directly.

Because Math::Series uses Math::Symbolic for its implementation, all
results will be Math::Symbolic objects which may contain other variables
than the sequence variable and the iterator variable.

Each Math::Series object is an iterator to iterate over the elements of
the series starting at the first element (which was specified by the
starting element, the second argument to the new() constructor). It offers
facilities to cache all calculated elements and access any element
directly, though unless the element has been cached in a previous
calculation, this is just a shortcut for repeated use of the iterator.