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New Mersenne Prime discovered (probably)

(www.mersenne.org)
359 points sdsykes | 1 comments | 16 Oct 24 11:51 UTC | HN request time: 0s | source
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stevefan1999 ◴[19 Oct 24 06:39 UTC] No.41886077[source]▶
But why do we have to "discover" it when we know the formula would be 2^N - 1...? Are we trying to prove a corollary or what?
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aaronmdjones ◴[19 Oct 24 06:45 UTC] No.41886104[source]▶
Not all 2^N - 1 are prime. For example, N=18 makes 2^N - 1 = 262143, which can also be written as 3^3 * 7 * 19 * 73 (not prime).
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stevefan1999 ◴[19 Oct 24 06:46 UTC] No.41886111[source]▶
Oh, right, all Mersenne number is in the form of 2^N -1, but Mersenne prime is Mersenne number plus being prime
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1. mort96 ◴[19 Oct 24 10:46 UTC] No.41887050[source]▶
And we look for Mersenne primes, AFAIU, mainly because Mersenne numbers are more likely to be prime than other numbers, so it's easier to find big primes that way.