--- In

primenumbers@yahoogroups.com,

Kevin Acres <research@...> wrote:

> A review of logs of 14+ chains gives me 17 15/16 amongst 226 14/16.

> Some of these are outside of my preferred x < 51561510 search area,

> where the yield of 15/16 becomes somewhat less.

Some way back, you reported using a wheel of size 510510 = 17#

and you reported the factorization

> [16, 3052362829787719304602274593,

> [43, 1; 80048363, 1; 886778685131718377, 1]]

In such a case,

prod(p=2,17,1-isprime(p)/p)*log(3052362829787719304602274593) =~ 11.4

estimates the mean number of 15's that you might need for a 16.

By my reckoning you now have about 23 runs of 15.

The a priori probability of a 16th prime was about

1 - exp(-23/11.4) = 87%

so it appears that you have been unlucky.

David