Andrzej Borucki andr1972

## euler_phi.cpp
/*
 * Euler's totient function phi(n).
 * http://en.wikipedia.org/wiki/Euler%27s_totient_function
 *
 * This is an *EXTREMELY* fast function and uses
 * several tricks to recurse.
 *
 * It assumes you have a list of primes and a fast
 * isprime() function.  Typically, you use a bitset
 * to implement the sieve of Eratosthenes and use
	/*
	* Euler's totient function phi(n).
	* http://en.wikipedia.org/wiki/Euler%27s_totient_function
	*
	* This is an EXTREMELY fast function and uses
	* several tricks to recurse.
	*
	* It assumes you have a list of primes and a fast
	* isprime() function. Typically, you use a bitset
	* to implement the sieve of Eratosthenes and use