About the actual number of primes (3)

PRIME NUMBER SERIES 8

About the actual number of primes (1)

The prime function \pi(n_{max})

 

The prime function \pi(n_{max}) is defined as the number of all primes p that are not greater than 2n_{max}+3.

The prime function \pi(n_{max}) provides for n_{max} ∈ ℕ the exact number of all primes up to a choosed value of n_{max}. It does not deal with approximations but with true values.

\pi(n_{max})=2+\sum\limits_{n=1}^{n_{max}}t(n)

Legend:

\sum\limits_{n=1}^{n_{max}}t(n) = Sum of all results of t(n) from n=1 up to the choosed nmax

Proof:

With the aid of the deterministic test function t(n) every t(n) is determined from n=1 up to the choosed n_{max} and then added up. Because t(n) provides only the values 0 for not prime and 1 for prime the result is the total number of primes from n=1 up to a choosed n_{max}. Because it is not allowed to use n=0 in t(n) 0 is put into 2n+3:

2*0+3=3

And up to the number 3 there are exactl 2 primes: 2 and 3. Therefore the 2 in the function \pi(n_{max}).

What had to be proved.

 

Munich, 24 October 2022

Gottfried Färberböck