MMMp=222p−1−1,p≥1 and either a prime or a non-prime
p=1,2221−1−1=4−1=3 is a prime
p=2,2222−1−1=16−1=15= a prime
p=3,2223−1−1=65536−1=65535= a prime
p=4,2224−1−1=1.15792089×1077−1=1.15792089×1077= a prime
p=5,2225−1−1=265536−1= a prime:
Therefore, there is no triple Mersenne prime where p is a prime, however, when p=1, a non-prime, it produces a prime. I have also discovered Triple Mersenne Numbers!
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Comments
@Yajat Shamji, why is it undefined? Its value is still 2216−1
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Trying to find that out now, I have further simplified it to 265536−1. @Aryan Sanghi
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It is very big, but that is defined, isn't it? Also, maybe at p = 11, it is a prime, but so big we can't evaluate, isn't it?
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@Aryan Sanghi.
What program you got? You sound very confident,Log in to reply
a2−b2 which can be factored as (a + b)(a - b). I hope I explained well. :)
Actually above number is defined, codes can't evaluate that much big numbers accurately(I do code and that's why I am saying). Above number is composite for every positive integer p as it can be written of formLog in to reply
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p=4 is a prime - let me check first.
I will check but I believe thatYou just checked for numbers 2,3,4,5 then how do you know that there can't be any prime after that?
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As it can be written of form a² - b² which can be factored into (a + b)(a - b)
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That is OK, but the proof in the note is not valid in my opinion.
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Just checking for some numbers is not a proof, I think it should be done algebraically.
You can read the long discussion we had in previous comment.
@Yajat Shamji, good job!! I never thought of p = 1.
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@Aryan Sanghi, what was the proof you were telling of there? I wish to know it!
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Simply that 2^2^2^(p-1) can be written as a² and 1 can be written as 1² which can be factored to (a + 1)(a -1).
I am making a note on Quadruple Mersenne Numbers and Primes. What do you think, @Aryan Sanghi, @Vinayak Srivastava?
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I guess you should rather post a question on it.
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What should the question be? @Aryan Sanghi
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What should the question be? @Vinayak Srivastava
In mathematics it is not sufficient to check only some cases to prove something, either you check for all primes (which are infinite), or either you give a mathematical proof so that the statement can mathematically be accepted.
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@Zakir Husain, thank you so much for reminding me but I think you should ask @Aryan Sanghi. He has got the proof.
@Mahdi Raza, @Alak Bhattacharya, @Gandoff Tan, @Hamza Anushath, @Aryan Sanghi
Will nobody comment on the fact that I have found Triple Mersenne numbers? @Vinayak Srivastava, @Aryan Sanghi
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Can you tell any such prime you have discovered? :)
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I haven't discovered any prime as of yet.
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2131072−1 is undefined according to all calculators or is above their amount of numbers limit.
I am working on it - currentlyLog in to reply
@Aryan Sanghi said, 2131072 is a square and so it will be a difference of two squares. Also, a−b=1, so it will have at least 2 factors other than itself and 1.
It is not prime. AsLog in to reply
n=1, then 2220−1=221−1=4−1=3, which is prime. I don't know of any other case.
There won't be any prime of such type, except whenLog in to reply
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@Yajat Shamji to see.)
But what is the flaw in my comment? (I know it, you know it, I want1 is not a prime - look at the note now!
I knowLog in to reply
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