explanation

[eljose79]

yes ins the so called prime-number counting function that is

Sum over all the prime numbers less than a given number x of f(x)=1

in fact my calculation is easy got from the formula:

S(p)Exp(-sp)=L(Pi(x)) where L is the laplace transform and s(p) means the sum over all primes of the function exp(-sp)

i have got a formula to approach Pi(x) for all x.

[Lonewolf]

Actually, I have a problem related to Pi(x) that has been bothering me for some time. Given x is the product of two primes, and we know the value of Pi(X), how can we calculate the prime factors of x? Any help would be appreciated.