#!/usr/bin/perl -w

# a not too bad approximation to the number of primes 
# less than N is approximately N/log(N).  Better methods 
# exist, but none are as simple...

my $n1 = 10**8;
my $n2 = 2**32;

$\="\n";

# ~ 5428681 
print "Number of primes less than $n1 is ",int($n1/log($n1));

# ~ 193635250
print "Number of primes less than $n2 is ",int($n2/log($n2));

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In reply to Re^2: Simple primality testing by Anonymous Monk
in thread Simple primality testing by ambrus

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