Re: Q:About primes?

"Phil Carmody" <thefatphil_demunged@xxxxxxxxxxx> wrote in message
news:87irsxk45d.fsf@xxxxxxxxxxxxxxxxxxxxxxx
> Dan <30pack@xxxxxxxxxxxxx> writes:
>> Q:About primes?
>>
>> Why does a certain large prime require much more
>> processing time to verify its primality than one that
>> is more than 60 times its size?
>>
>> e.g.
>>
>> This prime below with 749 digits required 17+ hours to
>> establish its primality.
>>
> ...
>>
>> Whereas this prime below with 751 digits that is more
>> than 60 times the size of the above prime
>
> What on earth are you gibbering on about?
>
> A 751-digit prime is roughly 1.0026 times the size of a 749-digit number.
>
> Phil
Eh?
10^751 / 10^749 = 10^2

Joe



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