From this we see that r ( \\ displaystyle r ) is any even integer .
That s and t are factors of r 2 2 ( \\ displaystyle ( \\ tfrac ( r ^ ( 2 ) ) ( 2 ) ) ) .
From this we see that r ( \\ displaystyle r ) is any even integer and that s and t are factors of r 2 2 ( \\ displaystyle ( \\ tfrac ( r ^ ( 2 ) ) ( 2 ) ) ) .