16, 4, 1, 1/4, what is the 6th term of this geometric sequence?

Well the rule for any geometric sequence is:

a(n)=ar^(n-1), a=initial term, r=common ratio, n=term number.

Here we have a common ratio of:

4/16=1/4=(1/4)/1=r=1/4 and an initial value of 16 so the formula becomes:

a(n)=16(1/4)^(n-1) so the sixth term would be:

a(6)=16(1/4)^5

a(6)=16/1024

a(6)=1/64

12, Y=2 X=1, starts at 12, rate is  (12+(2*Y) + (1*X) )