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Old 2021-09-18, 23:29   #1
LarsNet
 
Mar 2021

22·11 Posts
Minus 3x a mersenne prime seems to have a prime nearby by less than twice the mersenne number

I noticed this and wondered if anyone has ever went on this path to find a large prime to put in the database. I haven't bought my rig yet to start working on the project for mersennes, but will soon and was just curious about this one as it seems fun to try maybe. Probably not enough cpu power for the is_prime tests, heh.

Quote:
In [2511]: for x in mersenne[0:21]:
...: z = 3 * 2**x-1
...: g = gmpy2.next_prime(z)
...: print(x, g-z)
...:
3 6
5 2
7 6
13 18
17 26
19 6
31 24
61 48
89 44
107 170
127 18
521 546
607 510
1279 18
2203 1964
2281 2748
3217 546
4253 1356
4423 2720
I just did the math and see why such a search path wouldn't be very fruitful, nevermind :-)

Last fiddled with by LarsNet on 2021-09-18 at 23:32
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