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No. of distinct prime factors and no. of prime factors

Source: China Mathematical Olympiad 2014 Q4

December 22, 2013
inductionlogarithmsalgebranumber theory proposednumber theoryChina

Problem Statement

Let n=p1a1p2a2ptatn=p_1^{a_1}p_2^{a_2}\cdots p_t^{a_t} be the prime factorisation of nn. Define ω(n)=t\omega(n)=t and Ω(n)=a1+a2++at\Omega(n)=a_1+a_2+\ldots+a_t. Prove or disprove: For any fixed positive integer kk and positive reals α,β\alpha,\beta, there exists a positive integer n>1n>1 such that i) ω(n+k)ω(n)>α\frac{\omega(n+k)}{\omega(n)}>\alpha ii) Ω(n+k)Ω(n)<β\frac{\Omega(n+k)}{\Omega(n)}<\beta.