$1,000,000 problem :: Gauss :: Counting the primes  
         
     

Gauss changed the question: Instead of "where is the next prime?" he asked "how many primes are there less than 10, 100, 1000 or any number N?"

N Number of primes from 1 up to N, often referred to as (N) On average, how many numbers you need to count before you expect a prime number
10 4 2.5
100 25 4.0
1,000 168 6.0
10,000 1,229 8.1
100,000 9,592 10.4
1,000,000 78,498 12.7
10,000,000 664,579 15.0
100,000,000 5,761,455 17.4
1,000,000,000 50,847,534 19.7
10,000,000,000 455,052,511 22.0

The last column shows the probability that a number chosen at random around N is a prime number.

Can you spot a pattern beginning to emerge in the last column?
 
 
 
 
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