In a message dated 18/01/2005 19:55:40 GMT Standard Time,

mcnamara_gio@... writes:

let p be a prime number and r is product of all primes from2 including p

r=2*3*5*7*......*p s is anumber so that s>r+1 and s is prime. If

t=s-r then t is prime. Is this fact proved?

No, because it is false.

Take p = , so r = 210.

Take s=331 which is >211 and prime.

Then t = s-r=121 which is not prime.

Time taken to find this exception with a list of small primes: 1.5 mins.

Perhaps you could have had the fun of doing a quick check before posting?

-Mike Oakes

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