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Difference between revisions of "Liskovets-Gallot conjectures"
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==Definitions== | ==Definitions== | ||
− | [[Valery Liskovets]] studied the list of {{Kbn|+| | + | [[Valery Liskovets]] studied the list of {{Kbn|+|k|n}} primes and observed, that the {{Vk}}'s ({{Vk}} divisible by 3) |
got an irregular contribution of odd and even exponents yielding a prime. | got an irregular contribution of odd and even exponents yielding a prime. | ||
− | Examples: (for 1 | + | Examples: (for 1 ≤ {{Vn}} ≤ 100000) |
{| class="wikitable" | {| class="wikitable" | ||
− | ! | + | !{{Vk}}-value!!# odd!!# even |
|- | |- | ||
|51||38||5 | |51||38||5 | ||
Line 23: | Line 23: | ||
So Liskovets formulated the conjecture: | So Liskovets formulated the conjecture: | ||
− | <blockquote>'''There exist | + | <blockquote>'''There exist {{Vk}}, 3|{{Vk}}, such that primes {{Kbn|+|k|n}} do exist but only with odd {{Vn}}/only with even {{Vn}}.'''</blockquote> |
− | [[Yves Gallot]] extended this for {{Kbn| | + | [[Yves Gallot]] extended this for {{Kbn|k|n}} numbers and gave also the first solutions as: |
− | :{{Kbn|+| | + | :{{Kbn|+|k|n}} is composite for all even {{Vn}} for {{Vk}}=[[Proth prime 66741|66741]] |
− | :{{Kbn|+| | + | :{{Kbn|+|k|n}} is composite for all odd {{Vn}} for {{Vk}}=[[Proth prime 95283|95283]] |
− | :{{Kbn| | + | :{{Kbn|k|n}} is composite for all even {{Vn}} for {{Vk}}=[[Riesel prime 39939|39939]] |
− | :{{Kbn| | + | :{{Kbn|k|n}} is composite for all odd {{Vn}} for {{Vk}}=[[Riesel prime 172677|172677]] |
==Proof== | ==Proof== | ||
− | The verification of these conjectures has to be done in the same manner like the [[Riesel problem]]: find a prime for all | + | The verification of these conjectures has to be done in the same manner like the [[Riesel problem]]: find a prime for all {{Vk}}-values less than the given with the needed condition. |
==Search== | ==Search== |
Revision as of 16:22, 7 September 2020
Contents
Definitions
Valery Liskovets studied the list of k•2n+1 primes and observed, that the k's (k divisible by 3) got an irregular contribution of odd and even exponents yielding a prime.
Examples: (for 1 ≤ n ≤ 100000)
k-value | # odd | # even |
---|---|---|
51 | 38 | 5 |
231 | 51 | 9 |
261 | 56 | 14 |
87 | 2 | 36 |
93 | 1 | 38 |
177 | 8 | 46 |
So Liskovets formulated the conjecture:
There exist k, 3|k, such that primes k•2n+1 do exist but only with odd n/only with even n.
Yves Gallot extended this for k•2n-1 numbers and gave also the first solutions as:
- k•2n+1 is composite for all even n for k=66741
- k•2n+1 is composite for all odd n for k=95283
- k•2n-1 is composite for all even n for k=39939
- k•2n-1 is composite for all odd n for k=172677
Proof
The verification of these conjectures has to be done in the same manner like the Riesel problem: find a prime for all k-values less than the given with the needed condition.
Search
The current search is maintained by the Conjectures 'R Us project and can be found here.
Links
- Problem 36 "The Liskovets-Gallot numbers" from PP&P connection by Carlos Rivera