LAST EDITED ON Aug-08-01 AT 10:52 PM (EST)

>My
>gut feel tells me that
>it could have something to
>do with the range of
>the given number ie

Right

><=4,
><=16, <=64 <=256 and a
>div()/mod() in the resultant formula.
>But then I may be
>totally wrong.

You are, but not totally.

The relevant ranges are 4, 8, 16, 32, ...

>For eg: if <=4 then seems
>to be 2*n-3
>
>For 4<n<=16 seems to be 2n-4

For 8, it's 11. How does it fit with your formula?

You can prove by induction that for N = 2n, n > 1, that 3N/2 - 1 is a sufficient number of calls. Whether it's minimal I do not know. Whether you can interpolate between the powers of 2, I do not know either.