$\"\"$

\

An explicit formula for this sequence is $\"\"$ .

\

(a) Find the first five terms of the sequence.

\

Substitute $\"\"$ in $\"\"$ .

\

$\"\"$ .

\

Substitute $\"\"$ in $\"\"$ .

\

$\"\"$ .

\

Substitute $\"\"$ in $\"\"$ .

\

$\"\"$

\

Substitute $\"\"$ in $\"\"$ .

\

$\"\"$

\

Substitute $\"\"$ in $\"\"$ .

\

$\"\"$ .

\

The first five terms of the sequence are $\"\"$ .

\

$\"\"$

\

(b) Find the how many rounds of referrals the entire student body had a Web page.

\

The school has $\"\"$ students.

\

Substitute $\"\"$ in $\"\"$ .

\

$\"\"$

\

Substitute $\"\"$ in $\"\"$ .

\

$\"\"$ .

\

The round of referrals are

\

$\"\"$ .

\

$\"\"$ .

\

$\"\"$ .

\

$\"\"$ .

\

$\"\"$ .

\

After 5 rounds of referrals, then total number of new Web pages is greater than the population of the school .

\

Hence $\"\"$ .

\

$\"\"$

\

(a) The first five terms of the sequence are $\"\"$ .

\

(b) After 5 rounds of referrals, then total number of new Web pages is greater than the population of the school .