Math Is Fun Forum
  Discussion about math, puzzles, games and fun.   Useful symbols: ÷ × ½ √ ∞ ≠ ≤ ≥ ≈ ⇒ ± ∈ Δ θ ∴ ∑ ∫ • π ƒ -¹ ² ³ °

You are not logged in.

#1 2019-01-13 03:29:21

Primenumbers
Member
Registered: 2013-01-22
Posts: 147

If 2p + 1 is a factor of 2^p - 1 then it is prime, proof.

If an integer, 2p + 1, where p is a prime number, is a divisor of the Mersenne number

, then 2p + 1 is a prime number.

My argument is that because divisors of the Mersenne number

can’t be < p if p is a prime number. Therefore if 2p +1 is a divisor of
it has no divisors as p is > the square root of 2p + 1. This will therefore make 2p + 1 a prime number.

Is this proof correct?

Last edited by Primenumbers (2019-01-13 03:42:20)


"Time not important. Only life important." - The Fifth Element 1997

Offline

Board footer

Powered by FluxBB