when is 24m+7 prime ?
 

Is there a property of x that tells when 24m+7 could be prime ? That is what I want to know today. I know [url]http://oeis.org/A139483[/url] is when it is prime but is there a way to know when it isn't prime ? If so what values wouldn't work in [url]http://oeis.org/A002450[/url] because 24m+7 with m taking on these values is what produces every odd indexed Mersenne number.

[QUOTE=science_man_88;246996]Is there a property of x that tells when 24m+7 could be prime ? That is what I want to know today. I know [URL]http://oeis.org/A139483[/URL] is when it is prime but is there a way to know when it isn't prime ? If so what values wouldn't work in [URL]http://oeis.org/A002450[/URL] because 24m+7 with m taking on these values is what produces every odd indexed Mersenne number.[/QUOTE]If you told us what "x" is, we may be able to answer you. Until then, we don't have a hope.

[QUOTE=xilman;247002]If you told us what "x" is, we may be able to answer you. Until then, we don't have a hope.[/QUOTE]

sorry typo it should be m

[QUOTE=science_man_88;247027]sorry typo it should be m[/QUOTE]

24m+7 can be prime if m != 0 mod 7

[QUOTE=R.D. Silverman;247041]24m+7 can be prime if m != 0 mod 7[/QUOTE]

Thank you, that knocks every third one from the list by the looks of it. Want me to continue further ? I see what you mean though now that knocks out all 6x+9 indexes of Mersennes the first set eliminated after the even numbers. okay so i may be able to work that out for non prime indexes so it's the indexes that can create prime exponents that gives the difficulties. you've given me a lesson i should have known but it's a nice refresher.

[QUOTE=science_man_88;247044]Thank you, that knocks every third one from the list by the looks of it. Want me to continue further ? I see what you mean though now that knocks out all 6x+9 indexes of Mersennes the first set eliminated after the even numbers. okay so i may be able to work that out for non prime indexes so it's the indexes that can create prime exponents that gives the difficulties. you've given me a lesson i should have known but it's a nice refresher.[/QUOTE]

What you are doing is pointless. For two reasons:

(1) You do not know what you are doing.
(2) It amounts to nothing more than eliminating candidates by trial
division by small potential divisors.

[QUOTE=R.D. Silverman;247049]What you are doing is pointless. For two reasons:

(1) You do not know what you are doing.
(2) It amounts to nothing more than eliminating candidates by trial
division by small potential divisors.[/QUOTE]

I know what I'm doing I thought someone was about to point out it was "pointless" 24m+7 works out to a odd indexed mersenne number if you plug in m = [url]http://oeis.org/A002450[/url]. but if you think it's pointless i guess i have no point in trying to talk to you reasonably.

[QUOTE=science_man_88;247051]I know what I'm doing
[/QUOTE]

No, you don't. You are so lacking in basic mathematical knowledge
that everything you do is essentially just noise.


[QUOTE]
I thought someone was about to point out it was "pointless" 24m+7 works out to a odd indexed mersenne number if you plug in m = [url]http://oeis.org/A002450[/url]. but if you think it's pointless i guess i have no point in trying to talk to you reasonably.[/QUOTE]

You haven't tried reason yet. All I see is nonsense.

And you also need to learn to [b]accept[/b] what experts tell you.
I am not the only one with whom you ignorantly argue.

Stop your arrogance.

[QUOTE=R.D. Silverman;247055]No, you don't. You are so lacking in basic mathematical knowledge
that everything you do is essentially just noise.




You haven't tried reason yet. All I see is nonsense.

And you also need to learn to [b]accept[/b] what experts tell you.
I am not the only one with whom you ignorantly argue.

Stop your arrogance.[/QUOTE]

from what I've seen of your personality I can say that from my experience around anyone you find less experienced you act like a bully looking for a fight while having the principal as your best friend not willing to expel you from the school.

[QUOTE=science_man_88;247057]from what I've seen of your personality I can say that from my experience around anyone you find less experienced you act like a bully looking for a fight while having the principal as your best friend not willing to expel you from the school.[/QUOTE]

On the contrary. There was an Israeli student with the math subforum
whom I very patiently led through many exercizes in high school level
mathematics as well as elementary number theory.

The difference is in [i]attitude[/i], and yours sucks. Big time.

I do admit total disdain for those (such as yourself) who are unwilling
to do any reading and learning. You are willfully ignorant.

The issue is [b]NOT[/b] "less experience" [as you claim], but a
[b]very[/b] stubborn ignorance combined with arrogance.

[QUOTE=R.D. Silverman;247058]who are unwilling
to do [B][U][I][COLOR="Red"][SIZE="7"]any[/SIZE][/COLOR][/I][/U][/B] reading and learning..[/QUOTE]

I have done a bit of reading I've even followed links to sites about a topic to learn but that didn't help me learn much.