Two sequences of integers and condition for prime numbers.
Source: ILL 1979-49
June 5, 2011
inequalitiesnumber theory unsolvednumber theory
Problem Statement
Let there be given two sequences of integers fi(1),fi(2),⋯(i=1,2) satisfying:
(i)fi(nm)=fi(n)fi(m) if gcd(n,m)=1;
(ii) for every prime P and all k=2,3,4,⋯, fi(Pk)=fi(P)fi(Pk−1)−P2f(Pk−2).
Moreover, for every prime P:
(iii)f1(P)=2P,(iv)f2(P)<2P.
Prove that ∣f2(n)∣<f1(n) for all n.