In the infinite sequence
a, b, (a + b)/2, (a + 3b)/4, . . .
each term after the second is the arithmetic mean of the two previous terms.

Find the limit of the sequence in terms of real numbers a and b.

(In reply to spoiler by Ady TZIDON)

But the sequence is not defined as (a+z*b)/(z+1).

Posted by Charlie on 2007-05-23 10:09:46