For any positive integer $n>3$, there exists at least $1$ integer $k$ such that $n+k$ and $n-k$ are...
$begingroup$
How to prove the following conjecture:
For any positive integer $n>3$, there exists at least $1$ integer $k$ such that $n+k$ and $n-k$ are both primes.
Any hint, idea or reference would be greatly appreciated!
number-theory prime-numbers prime-gaps
$endgroup$
add a comment |
$begingroup$
How to prove the following conjecture:
For any positive integer $n>3$, there exists at least $1$ integer $k$ such that $n+k$ and $n-k$ are both primes.
Any hint, idea or reference would be greatly appreciated!
number-theory prime-numbers prime-gaps
$endgroup$
$begingroup$
Do you mean that $n+k$ AND $n-k$ are prime or just $n+k$ OR $n-k$ is prime?
$endgroup$
– stressed out
Jan 2 at 0:28
$begingroup$
both are primes
$endgroup$
– François Huppé
Jan 2 at 0:32
2
$begingroup$
But then it's false for $n<3$. Isn't it?
$endgroup$
– stressed out
Jan 2 at 0:32
$begingroup$
@stressed you are right
$endgroup$
– François Huppé
Jan 2 at 0:35
add a comment |
$begingroup$
How to prove the following conjecture:
For any positive integer $n>3$, there exists at least $1$ integer $k$ such that $n+k$ and $n-k$ are both primes.
Any hint, idea or reference would be greatly appreciated!
number-theory prime-numbers prime-gaps
$endgroup$
How to prove the following conjecture:
For any positive integer $n>3$, there exists at least $1$ integer $k$ such that $n+k$ and $n-k$ are both primes.
Any hint, idea or reference would be greatly appreciated!
number-theory prime-numbers prime-gaps
number-theory prime-numbers prime-gaps
edited Jan 2 at 2:58
François Huppé
asked Jan 2 at 0:25
François HuppéFrançois Huppé
365111
365111
$begingroup$
Do you mean that $n+k$ AND $n-k$ are prime or just $n+k$ OR $n-k$ is prime?
$endgroup$
– stressed out
Jan 2 at 0:28
$begingroup$
both are primes
$endgroup$
– François Huppé
Jan 2 at 0:32
2
$begingroup$
But then it's false for $n<3$. Isn't it?
$endgroup$
– stressed out
Jan 2 at 0:32
$begingroup$
@stressed you are right
$endgroup$
– François Huppé
Jan 2 at 0:35
add a comment |
$begingroup$
Do you mean that $n+k$ AND $n-k$ are prime or just $n+k$ OR $n-k$ is prime?
$endgroup$
– stressed out
Jan 2 at 0:28
$begingroup$
both are primes
$endgroup$
– François Huppé
Jan 2 at 0:32
2
$begingroup$
But then it's false for $n<3$. Isn't it?
$endgroup$
– stressed out
Jan 2 at 0:32
$begingroup$
@stressed you are right
$endgroup$
– François Huppé
Jan 2 at 0:35
$begingroup$
Do you mean that $n+k$ AND $n-k$ are prime or just $n+k$ OR $n-k$ is prime?
$endgroup$
– stressed out
Jan 2 at 0:28
$begingroup$
Do you mean that $n+k$ AND $n-k$ are prime or just $n+k$ OR $n-k$ is prime?
$endgroup$
– stressed out
Jan 2 at 0:28
$begingroup$
both are primes
$endgroup$
– François Huppé
Jan 2 at 0:32
$begingroup$
both are primes
$endgroup$
– François Huppé
Jan 2 at 0:32
2
2
$begingroup$
But then it's false for $n<3$. Isn't it?
$endgroup$
– stressed out
Jan 2 at 0:32
$begingroup$
But then it's false for $n<3$. Isn't it?
$endgroup$
– stressed out
Jan 2 at 0:32
$begingroup$
@stressed you are right
$endgroup$
– François Huppé
Jan 2 at 0:35
$begingroup$
@stressed you are right
$endgroup$
– François Huppé
Jan 2 at 0:35
add a comment |
2 Answers
2
active
oldest
votes
$begingroup$
I suspect the OP means $n + k$ AND $n - k$. If so, this is the same as the strong Goldbach conjecture, which is a very well-known unsolved problem. In particular, if $n + k$ and $n - k$ are both prime, their sum is $2n$. Also, every positive even integer $gt 2$ is of the form $2n$, for some positive integer $n$. Thus, if the OP's conjecture holds, so does the Goldbach conjecture.
$endgroup$
$begingroup$
@FrançoisHuppé I am not quite sure what you are stating. I never wrote that, or meant to imply, it was "trivial". I just explained that it is a slightly stronger conjecture than the strong Goldbach conjecture. I was not aware from your question that you already knew this, and I didn't mean to imply you did not because there is no way for me to know what you have already figured out apart from what you wrote.
$endgroup$
– John Omielan
Jan 2 at 0:49
$begingroup$
sorry it came out wrong, i should add this in my question instead :) in fact your answer is perfect
$endgroup$
– François Huppé
Jan 2 at 0:58
$begingroup$
@FrançoisHuppé No worries about your earlier comment. Also, I originally thought your question said $k$ is a positive integer. Perhaps it did then but was changed since as I see the question has an edit time after my answer. Regardless, as the question text now does not require this, it means your conjecture is the same as the Goldbach one, so I have changed my answer accordingly to no longer say yours is a slightly stronger conjecture.
$endgroup$
– John Omielan
Jan 2 at 7:58
add a comment |
$begingroup$
I would do some searching in the On-Line Encyclopedia of Integer Sequences (OEIS). Give me a couple of minutes...
Okay, here's one pertinent result: http://oeis.org/A020483 Least prime $p$ such that $p + 2n$ is also prime. According to Jens Kruse Andersen, "It is conjectured that $a(n)$ always exists."
$endgroup$
add a comment |
Your Answer
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2 Answers
2
active
oldest
votes
2 Answers
2
active
oldest
votes
active
oldest
votes
active
oldest
votes
$begingroup$
I suspect the OP means $n + k$ AND $n - k$. If so, this is the same as the strong Goldbach conjecture, which is a very well-known unsolved problem. In particular, if $n + k$ and $n - k$ are both prime, their sum is $2n$. Also, every positive even integer $gt 2$ is of the form $2n$, for some positive integer $n$. Thus, if the OP's conjecture holds, so does the Goldbach conjecture.
$endgroup$
$begingroup$
@FrançoisHuppé I am not quite sure what you are stating. I never wrote that, or meant to imply, it was "trivial". I just explained that it is a slightly stronger conjecture than the strong Goldbach conjecture. I was not aware from your question that you already knew this, and I didn't mean to imply you did not because there is no way for me to know what you have already figured out apart from what you wrote.
$endgroup$
– John Omielan
Jan 2 at 0:49
$begingroup$
sorry it came out wrong, i should add this in my question instead :) in fact your answer is perfect
$endgroup$
– François Huppé
Jan 2 at 0:58
$begingroup$
@FrançoisHuppé No worries about your earlier comment. Also, I originally thought your question said $k$ is a positive integer. Perhaps it did then but was changed since as I see the question has an edit time after my answer. Regardless, as the question text now does not require this, it means your conjecture is the same as the Goldbach one, so I have changed my answer accordingly to no longer say yours is a slightly stronger conjecture.
$endgroup$
– John Omielan
Jan 2 at 7:58
add a comment |
$begingroup$
I suspect the OP means $n + k$ AND $n - k$. If so, this is the same as the strong Goldbach conjecture, which is a very well-known unsolved problem. In particular, if $n + k$ and $n - k$ are both prime, their sum is $2n$. Also, every positive even integer $gt 2$ is of the form $2n$, for some positive integer $n$. Thus, if the OP's conjecture holds, so does the Goldbach conjecture.
$endgroup$
$begingroup$
@FrançoisHuppé I am not quite sure what you are stating. I never wrote that, or meant to imply, it was "trivial". I just explained that it is a slightly stronger conjecture than the strong Goldbach conjecture. I was not aware from your question that you already knew this, and I didn't mean to imply you did not because there is no way for me to know what you have already figured out apart from what you wrote.
$endgroup$
– John Omielan
Jan 2 at 0:49
$begingroup$
sorry it came out wrong, i should add this in my question instead :) in fact your answer is perfect
$endgroup$
– François Huppé
Jan 2 at 0:58
$begingroup$
@FrançoisHuppé No worries about your earlier comment. Also, I originally thought your question said $k$ is a positive integer. Perhaps it did then but was changed since as I see the question has an edit time after my answer. Regardless, as the question text now does not require this, it means your conjecture is the same as the Goldbach one, so I have changed my answer accordingly to no longer say yours is a slightly stronger conjecture.
$endgroup$
– John Omielan
Jan 2 at 7:58
add a comment |
$begingroup$
I suspect the OP means $n + k$ AND $n - k$. If so, this is the same as the strong Goldbach conjecture, which is a very well-known unsolved problem. In particular, if $n + k$ and $n - k$ are both prime, their sum is $2n$. Also, every positive even integer $gt 2$ is of the form $2n$, for some positive integer $n$. Thus, if the OP's conjecture holds, so does the Goldbach conjecture.
$endgroup$
I suspect the OP means $n + k$ AND $n - k$. If so, this is the same as the strong Goldbach conjecture, which is a very well-known unsolved problem. In particular, if $n + k$ and $n - k$ are both prime, their sum is $2n$. Also, every positive even integer $gt 2$ is of the form $2n$, for some positive integer $n$. Thus, if the OP's conjecture holds, so does the Goldbach conjecture.
edited Jan 2 at 7:52
answered Jan 2 at 0:35
John OmielanJohn Omielan
3,5651215
3,5651215
$begingroup$
@FrançoisHuppé I am not quite sure what you are stating. I never wrote that, or meant to imply, it was "trivial". I just explained that it is a slightly stronger conjecture than the strong Goldbach conjecture. I was not aware from your question that you already knew this, and I didn't mean to imply you did not because there is no way for me to know what you have already figured out apart from what you wrote.
$endgroup$
– John Omielan
Jan 2 at 0:49
$begingroup$
sorry it came out wrong, i should add this in my question instead :) in fact your answer is perfect
$endgroup$
– François Huppé
Jan 2 at 0:58
$begingroup$
@FrançoisHuppé No worries about your earlier comment. Also, I originally thought your question said $k$ is a positive integer. Perhaps it did then but was changed since as I see the question has an edit time after my answer. Regardless, as the question text now does not require this, it means your conjecture is the same as the Goldbach one, so I have changed my answer accordingly to no longer say yours is a slightly stronger conjecture.
$endgroup$
– John Omielan
Jan 2 at 7:58
add a comment |
$begingroup$
@FrançoisHuppé I am not quite sure what you are stating. I never wrote that, or meant to imply, it was "trivial". I just explained that it is a slightly stronger conjecture than the strong Goldbach conjecture. I was not aware from your question that you already knew this, and I didn't mean to imply you did not because there is no way for me to know what you have already figured out apart from what you wrote.
$endgroup$
– John Omielan
Jan 2 at 0:49
$begingroup$
sorry it came out wrong, i should add this in my question instead :) in fact your answer is perfect
$endgroup$
– François Huppé
Jan 2 at 0:58
$begingroup$
@FrançoisHuppé No worries about your earlier comment. Also, I originally thought your question said $k$ is a positive integer. Perhaps it did then but was changed since as I see the question has an edit time after my answer. Regardless, as the question text now does not require this, it means your conjecture is the same as the Goldbach one, so I have changed my answer accordingly to no longer say yours is a slightly stronger conjecture.
$endgroup$
– John Omielan
Jan 2 at 7:58
$begingroup$
@FrançoisHuppé I am not quite sure what you are stating. I never wrote that, or meant to imply, it was "trivial". I just explained that it is a slightly stronger conjecture than the strong Goldbach conjecture. I was not aware from your question that you already knew this, and I didn't mean to imply you did not because there is no way for me to know what you have already figured out apart from what you wrote.
$endgroup$
– John Omielan
Jan 2 at 0:49
$begingroup$
@FrançoisHuppé I am not quite sure what you are stating. I never wrote that, or meant to imply, it was "trivial". I just explained that it is a slightly stronger conjecture than the strong Goldbach conjecture. I was not aware from your question that you already knew this, and I didn't mean to imply you did not because there is no way for me to know what you have already figured out apart from what you wrote.
$endgroup$
– John Omielan
Jan 2 at 0:49
$begingroup$
sorry it came out wrong, i should add this in my question instead :) in fact your answer is perfect
$endgroup$
– François Huppé
Jan 2 at 0:58
$begingroup$
sorry it came out wrong, i should add this in my question instead :) in fact your answer is perfect
$endgroup$
– François Huppé
Jan 2 at 0:58
$begingroup$
@FrançoisHuppé No worries about your earlier comment. Also, I originally thought your question said $k$ is a positive integer. Perhaps it did then but was changed since as I see the question has an edit time after my answer. Regardless, as the question text now does not require this, it means your conjecture is the same as the Goldbach one, so I have changed my answer accordingly to no longer say yours is a slightly stronger conjecture.
$endgroup$
– John Omielan
Jan 2 at 7:58
$begingroup$
@FrançoisHuppé No worries about your earlier comment. Also, I originally thought your question said $k$ is a positive integer. Perhaps it did then but was changed since as I see the question has an edit time after my answer. Regardless, as the question text now does not require this, it means your conjecture is the same as the Goldbach one, so I have changed my answer accordingly to no longer say yours is a slightly stronger conjecture.
$endgroup$
– John Omielan
Jan 2 at 7:58
add a comment |
$begingroup$
I would do some searching in the On-Line Encyclopedia of Integer Sequences (OEIS). Give me a couple of minutes...
Okay, here's one pertinent result: http://oeis.org/A020483 Least prime $p$ such that $p + 2n$ is also prime. According to Jens Kruse Andersen, "It is conjectured that $a(n)$ always exists."
$endgroup$
add a comment |
$begingroup$
I would do some searching in the On-Line Encyclopedia of Integer Sequences (OEIS). Give me a couple of minutes...
Okay, here's one pertinent result: http://oeis.org/A020483 Least prime $p$ such that $p + 2n$ is also prime. According to Jens Kruse Andersen, "It is conjectured that $a(n)$ always exists."
$endgroup$
add a comment |
$begingroup$
I would do some searching in the On-Line Encyclopedia of Integer Sequences (OEIS). Give me a couple of minutes...
Okay, here's one pertinent result: http://oeis.org/A020483 Least prime $p$ such that $p + 2n$ is also prime. According to Jens Kruse Andersen, "It is conjectured that $a(n)$ always exists."
$endgroup$
I would do some searching in the On-Line Encyclopedia of Integer Sequences (OEIS). Give me a couple of minutes...
Okay, here's one pertinent result: http://oeis.org/A020483 Least prime $p$ such that $p + 2n$ is also prime. According to Jens Kruse Andersen, "It is conjectured that $a(n)$ always exists."
answered Jan 2 at 5:08
Robert SoupeRobert Soupe
11.3k21950
11.3k21950
add a comment |
add a comment |
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$begingroup$
Do you mean that $n+k$ AND $n-k$ are prime or just $n+k$ OR $n-k$ is prime?
$endgroup$
– stressed out
Jan 2 at 0:28
$begingroup$
both are primes
$endgroup$
– François Huppé
Jan 2 at 0:32
2
$begingroup$
But then it's false for $n<3$. Isn't it?
$endgroup$
– stressed out
Jan 2 at 0:32
$begingroup$
@stressed you are right
$endgroup$
– François Huppé
Jan 2 at 0:35