By number-theoretical functions, we will understand integer-valued functions defined on the set of all integers. Are there number-theoretical functions f0(x),f1(x),f2(x),… such that every number theoretical function F(x) can be uniquely represented in the form
F(x)\equal{}\sum_{k\equal{}0}^{\infty}a_kf_k(x),
a0,a1,a2,… being integers? functionnumber theory proposednumber theory