Re: question on hash for objects such as tables and functions

[Francisco Olarte <folarte@...>]

Philippe:

On Wed, May 27, 2020 at 12:56 PM Philippe Verdy <verdyp@gmail.com> wrote:
> Le mer. 27 mai 2020 à 11:09, Francisco Olarte <folarte@peoplecall.com> a écrit :
>> On Tue, May 26, 2020 at 11:30 PM Philippe Verdy <verdyp@gmail.com> wrote:
>> > So now you can confirm that the factor 129 is not suitable as is is not prime (divisible by 3) even if it's a Mersenne number (=2^7+1).
>> To be strict, Mersenne numbers are -1, that +1 is an extension you
>> have put without proof.
> Wrong! I'm not inventing them !
> There are two series of Mersenne numbers:
> * Mn(p) = 2^p-1, often just noted M(p), and
> * Mp(p) = 2^p+1

As you seem to like internet quotes, a quick googling reveals:

https://mathworld.wolfram.com/MersennePrime.html
"A Mersenne prime is a Mersenne number, i.e., a number of the form
2^n-1 that is prime. "

https://oeis.org/wiki/Mersenne_numbers
"Mersenne numbers are numbers of the form 2 n  −  1, where nis a
nonnegative integer."

https://en.wikipedia.org/wiki/Mersenne_prime
"More generally, numbers of the form Mn = 2n − 1 without the primality
requirement may be called Mersenne numbers."

https://dlmf.nist.gov/27.18
"These algorithms are used for testing primality of Mersenne numbers, 2n-1,"

The nearer thing to your 2^n+1 I know off are Fermat Numbers, 2^(2^n)+1.

Can I see some place where 2^n+1 is called a Mersenne Number?

Fracisco Olarte.