http://demonstrations.wolfram.com/LogarithmicIntegralOnTheCriticalLine/ The Wolfram Demonstrations Project contains thousands of free interactive visualizations, with new entries added daily. In his 1859 paper "On the Number of Primes Less Than a Given Magnitude," Bernhard Riemann gave a formula involving his zeta function to determine the number of primes less than a specific number x. This Demonstration shows the behavior of the logarithmi... Contributed by: Brandon Carter