thoroughly newbie question

[rpjday <rpjday mindspring com>]

  having lived this long without ever having used a spreadsheet,
i'm sure this is a totally trivial question, but the docs don't seem
to explain it.

  i want to define a spreadsheet with an arbitrary number of
rows so that element A(n) = A(n-1) + B(n-1), and i want to define
this relationship across as many rows as i choose to put numeric
values into.

  i get the feeling this is related to relative versus absolute
cell referencing, which also confuses me.  any help would be appreciated.

rday