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2017-04-02, 01:31   #100
Jayder

Dec 2012

11616 Posts

Thank you very much Xyzzy! I do appreciate it. I had in mind something similar to a1call's suggestion, but if this is all that you can reasonably do with the forum software, I am grateful.

Quote:
 Originally Posted by science_man_88 there are times one might refer to a value that's a mersenne prime as the exponent as well like in double mersennes ( aka operazione doppi mersennes) there's a lot to factor in does spacing count etc. example is M48 could be the 48th mersenne prime or the 48th mersenne number # is often used to separate them I think but it's an important note. and in some forums like astronomy there's M48 (for messier object 48) to think about.
I would guess that discussion of Mersenne numbers with an exponent less than 100 would be incredibly rare. If links were to be automatically added, I would recommend that it not link for anything less than 100, or perhaps 1000. I also previously suggested that it only place a link where there is a prime number, which would eliminate M48, as well as M8388608. I think that it would only take a little work to eliminate the vast majority of these issues.

I would also hope that (were this ever to be implemented) this could be disabled or enabled in a post, just as smilies and parsing of links can be enabled or disabled under Miscellaneous Options. I would even encourage this to be turned off by default.

2017-04-02, 02:58   #101
a1call

"Rashid Naimi"
Oct 2015
Remote to Here/There

2·7·139 Posts

Quote:
 Originally Posted by Jayder Thank you very much Xyzzy! I do appreciate it. I had in mind something similar to a1call's suggestion, but if this is all that you can reasonably do with the forum software, I am grateful. I would guess that discussion of Mersenne numbers with an exponent less than 100 would be incredibly rare. If links were to be automatically added, I would recommend that it not link for anything less than 100, or perhaps 1000. I also previously suggested that it only place a link where there is a prime number, which would eliminate M48, as well as M8388608. I think that it would only take a little work to eliminate the vast majority of these issues. I would also hope that (were this ever to be implemented) this could be disabled or enabled in a post, just as smilies and parsing of links can be enabled or disabled under Miscellaneous Options. I would even encourage this to be turned off by default.
Matching primes would not be very straightforward. The only way I can think of would be to make a long string of all the primes to be matched, separated by a non numeric separator and running a match.

Wikipedia article on Regular-Expressions:

https://en.wikipedia.org/wiki/Regular_expression

 2017-04-02, 07:01 #102 a1call     "Rashid Naimi" Oct 2015 Remote to Here/There 2·7·139 Posts Copy the code: Code:  ​

Replace "microsoft" with "W3Schools" in the paragraph below:

exponent Bad Good Unk Sus Solo Mis worktodo 50248349 1 0 1 0 1 0 DoubleCheck=50248349,73,1 50956921 0 0 4 0 4 0 DoubleCheck=50956921,73,1 52479409 0 0 3 0 3 0 DoubleCheck=52479409,73,1 53167397 0 0 4 0 4 0 DoubleCheck=53167397,73,1 53312419 0 0 4 0 4 0 DoubleCheck=53312419,73,1 53576399 0 0 3 0 3 0 DoubleCheck=53576399,73,1 53902309 0 0 2 0 2 0 DoubleCheck=53902309,73,1

​ ​ Paste and replace the left frame here: https://www.w3schools.com/js/tryit.a...replace_regexp Then click "Run" Then click "Try it"
 2017-04-02, 08:46 #103 a1call     "Rashid Naimi" Oct 2015 Remote to Here/There 2·7·139 Posts Now that I think about it, you could run a primality test on the matched exponent and only insert the link if true.
2017-04-02, 21:13   #104
Jayder

Dec 2012

2×139 Posts

Quote:
 Originally Posted by a1call Now that I think about it, you could run a primality test on the matched exponent and only insert the link if true.
Right, it would take next to no time. But an upper bound would need to be fixed, the obvious answer being the current PrimeNet limit of 999,999,999.

Last fiddled with by Jayder on 2017-04-02 at 21:14

 2017-04-02, 22:20 #105 a1call     "Rashid Naimi" Oct 2015 Remote to Here/There 2·7·139 Posts Yes, the previous prime is 999,999,9673 and can be instantly checked at: https://www.mathsisfun.com/prime_numbers.html

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