At 10/24/2006 02:21 PM, Wayne Petrychyn wrote:

>1.  On the Status page: http://www.mersenne.org/status.htm the stats table 
>has ranges of numbers.  Does anyone know why the ranges are what they 
>are?  They aren't powers of 2 or of 10 but they seem to be non-arbitrary. 
>The first rew (other than the very first) are about 150,000 numbers, the 
>next groups almost 300,000 and the last few 550,000.

They represent the boundaries of the size of the FFT (Fast Fourier 
Transforms) lookup tables used to do the gargantuan divisions that would 
otherwise be impossible in a reasonable time.  The last column shows you 
the size of the FFT lookup table.  The first row in the table is a 
consolidation of "Many" FFT sizes below 768 -- consolidated because that 
range is entirely complete and double-checked.

>2.  The upper limit is 79,300,000.  Again a curious number.  Why this 
>number? 2 to the 26th would be about 67,000,000.

That's the largest number a 4K FFT lookup table can handle.

Jeff 


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