(So yes, π 2 and all other powers of π are periods.) But the story doesn't end here as it is believed that there are truly deep connections between values of zeta functions (or L-functions) and certain evaluations involving periods, such as π . read more
But the symbol [math]\pi[/math] not only refers to the ratio between circumference and diameter, it also refers to the prime counting function. [math]\pi(n)[/math] returns the number of primes less than or equal to n. read more
But the story doesn't end here as it is believed that there are truly deep connections between values of zeta functions (or L-functions) and certain evaluations involving periods, such as $\pi$. Another famous problem about primes is Sylvester's problem of which primes can be written as a sum of two rational cubes. read more