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Difference between revisions of "PrimeGrid Fermat Divisor Search"

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(Add info on ranges searched)
(Add note about even-n only searches + Fermat divisor for k=27 find)
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* 5 ≤ {{Vk}} ≤ 49 for {{Vn}} ≤ 9,000,000, with two exceptions:
 
* 5 ≤ {{Vk}} ≤ 49 for {{Vn}} ≤ 9,000,000, with two exceptions:
 
**{{Vk}} = 9 and 27 did not search even {{Vn}}-values, because they cannot produce Fermat divisors.<ref>[https://www.primegrid.com/forum_thread.php?id=8783 What primes can be Fermat divisors? - PrimeGrid Forums]</ref>
 
**{{Vk}} = 9 and 27 did not search even {{Vn}}-values, because they cannot produce Fermat divisors.<ref>[https://www.primegrid.com/forum_thread.php?id=8783 What primes can be Fermat divisors? - PrimeGrid Forums]</ref>
* {{Vk}} = 1323, 2187, 3125, 3267, 3375 for {{Vn}} ≤ 3,322,000
+
* {{Vk}} = 1323, 2187, 3267 for even<ref>https://www.primegrid.com/forum_thread.php?id=8778&nowrap=true#132677</ref> {{Vn}} ≤ 3,322,000
 +
* {{Vk}} = 3125, 3375 for {{Vn}} ≤ 3,322,000
 
* {{Vk}} = 19683 for {{Vn}} ≤ 4,000,000
 
* {{Vk}} = 19683 for {{Vn}} ≤ 4,000,000
  
Line 17: Line 18:
 
*2021-01-23: [[Proth prime 39|{{Kbn|+|39|8413422}}]]
 
*2021-01-23: [[Proth prime 39|{{Kbn|+|39|8413422}}]]
 
*2021-01-19: [[Proth prime 31|{{Kbn|+|31|8348000}}]]
 
*2021-01-19: [[Proth prime 31|{{Kbn|+|31|8348000}}]]
*2021-01-14: [[Proth prime 27|{{Kbn|+|27|7963247}}]]
+
*2021-01-14: [[Proth prime 27|{{Kbn|+|27|7963247}}]], divides F(7963245)
 
*2021-01-14: [[Proth prime 39|{{Kbn|+|39|7946769}}]]
 
*2021-01-14: [[Proth prime 39|{{Kbn|+|39|7946769}}]]
 
*2021-01-14: [[Proth prime 29|{{Kbn|+|29|7899985}}]]
 
*2021-01-14: [[Proth prime 29|{{Kbn|+|29|7899985}}]]

Revision as of 04:40, 16 June 2021

Fermat Divisor Search was a PrimeGrid project searching for large Fermat divisors. It began in September 2019, and ended in April 2021.[1]

Purpose

The project searched for Fermat divisors of the form k•2n+1, for the following ranges:[1]

  • 5 ≤ k ≤ 49 for n ≤ 9,000,000, with two exceptions:
    • k = 9 and 27 did not search even n-values, because they cannot produce Fermat divisors.[2]
  • k = 1323, 2187, 3267 for even[3] n ≤ 3,322,000
  • k = 3125, 3375 for n ≤ 3,322,000
  • k = 19683 for n ≤ 4,000,000

Completed status page

Found primes

See also

References

External links