Define a sequence where
an = the decimal expansion of e to n decimal places.
Find the first four terms of this sequence, starting with n = 1.
Ask your calculator for e or e1. It probably shows you something like
To get the nth term of the sequence, we copy this down to n decimal places. So
a1 = 2.7
a2 = 2.71
a3 = 2.718
a4 = 2.7182
The first four terms are
2.7, 2.71, 2.718, 2.7182.