Discrete Math
posted by Compstudent on .
So = 2
S1 = 5
Sn =  Sn  1 + nSn  2, n >_ 2
How do I interpret the value of n? Is this number equivalent to S1, S0, or 2? I have tried each option; finding S3 is difficult because I don't know what value to multiply Sn2 with, when solving for S2. Your assistance would be very helpful:)

Substitute n for the value you need, but you have to do them in order:
So = 2
S1 = 5
S_{2} =  S_{21} + 2S_{22}
=  S_{1} + 2S_{0}
= 5 + 2*2
= 1
S2=1
S3=S2+2*s1
=(1) + 2*5
=11
and so on.
Unfortunately, you will have to calculate all the terms in sequence for a recurrence relation UNLESS you solve for the sequence in terms of the initial terms.
I believe you are at the point where you need to be able to evaluate in sequence and understand the notations.
Sn =  Sn  1 + nSn  2, n >_ 2 
S2=1