Answer
$a_{1}=0;$
$a_{2}=\dfrac {3}{5};$
$a_{3}=\dfrac {4}{5};$
$a_{4}=\dfrac {15}{17};$
$a_{5}=\dfrac {12}{13}$
Work Step by Step
$a_{1}=\dfrac {1^{2}-1}{1^{2}+1}=0;$
$a_{2}=\dfrac {2^{2}-1}{2^{2}+1}=\dfrac {3}{5};$
$a_{3}=\dfrac {3^{2}-1}{3^{2}+1}=\dfrac {4}{5};$
$a_{4}=\dfrac {4^{2}-1}{4^{2}+1}=\dfrac {15}{17};$
$a_{5}=\dfrac {5^{2}-1}{5^{2}+1}=\dfrac {24}{26}=\dfrac {12}{13}$