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2022-11-15, 00:42
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#1 |
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Jan 2022
228 Posts |
new formula for prime numbers?
Hello everyone,
I found an interesting formula in a book. It is the formula n^2-9n+61. It produces a lot of prime numbers. Currently i am checking range 0k-100k Found a lot of primes! Hope to hear more about this. Best Regards. |
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2022-11-15, 04:46
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#2 |
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Romulan Interpreter
"name field"
Jun 2011
Thailand
3·23·149 Posts |
Please post here the largest prime you found.
Only one, please. Chose the largest, and tell us how you found it. |
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2022-11-15, 06:09
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#3 | |
"Serge"
Mar 2008
Phi(4,2^7658614+1)/2
3·7·479 Posts |
Quote:
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2022-11-15, 13:14
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#4 |
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Jan 2022
2·32 Posts |
largest prime number i found so far with n^2-9n+61
This is the largest prime number i found so far: (2^27450)^2-(9*(2^27450))+61
Currently i am checking k until 30k. I found the prime with openPFGW. Best Regards. |
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2022-11-15, 13:25
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#5 |
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Jan 2022
1810 Posts |
its not a formula you are right
You are right, it is not a formula but a sequence.
Best Regards. |
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2022-11-15, 14:28
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#6 |
Feb 2017
Nowhere
141258 Posts |
It's certainly not new.
n^2 - 9*n + 61 = (n-4)^2 - (n-4) + 41 is merely a shift of Euler's "prime-generating polynomial" n^2 - n + 41. |
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2022-11-16, 17:27
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#7 | |
Mar 2016
1101001002 Posts |
Quote:
For this special case I recommend a sieve procedure similar like the sieve of Eratosthenes: http://devalco.de/basic_polynomials/...?a=1&b=-1&c=41 For a more general point of view take: http://devalco.de/poly_sec.php If you want to speed up the finding for primes for f(n)=n²-n+41 I suggest a quadratic presieve and then the check for primes. Have a lot of fun with the theory and with the programming. |
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2022-11-17, 14:34
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#8 |
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Jan 2022
2·32 Posts |
sequence
Thank you!
I will start with it immediately. |
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2022-11-19, 19:35
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#9 |
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Jan 2022
2×32 Posts |
Siever
Hello everyone,
I made a siever for n^2-n+41. Its written in Python so its very slow. I am working on a c or freebasic version now. I keep you updated. |
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