A teacher places n seats to form the back row of a classroom layout. Each successive row contains two fewer seats than the preceding row. Find a formula, S(n), for the number of seats used in the...

A teacher placesn seats to form the back row of a classroom layout. Each successive row contains two fewer seats than the preceding row. Find a formula,

for the number of seats used in the layout. (Hint: The number of seats in the layout depends on whethern is odd or even.)

n is evenS(n)=
n is oddS(n)=