RE: [PrimeNumbers] Quadratic residue
> Given a prime p how does one find n such that 2^n+1 %p=0Yes there is. Do a google search for "discrete logarithm". "Baby steps giant
> If p=4K+1 then does n have to be k.
> Is there a method faster than factoring p-1 and then calculating
> 2^a+1 %p then 2^2*a+1 %p etc...
steps" and "silver pohlig hellman" are other useful search terms.
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