Let us consider the prime factorization of n. We define the sequence Fp(n) in
the following way. If the prime p appear with exponent 1 in the prime factorization
of n then Fp(n) = 1. In contrary case we put Fp(n) = 0. For example
F5(30) = F5(2.3.5) = 1, F5(100) = F5(22.52) = 0 and F5(6) = F5(2.3) = 0.
Clearly we have