Question

1/(1*3) + 1/(3*5) + 1/(5*7)= 3/7

come up with a formula S(n)

Answer 1

S(1) = 1/3

S(2) = 1/3 + 1/15 = 6/15 = 2/5
S(3) = 2/5 + 1/35 = 15/35 = 3/7
S(4) = 3/7 + 1/(7*9) = 4/9

mmmmh

looks like S(n) = n/(2n+1)