Suppose an=1(log2)p+(log3)p+...+(logn)p for n≥2 and p>0. For which values of p does ∑∞n=2an converge?
So, when p≤1, an≥1(n−1)(logn)p for n≥2. Let bn=1(n−1)(logn)p. Then ∑bn diverges since p≤1. Therefore by comparison test ∑an diverges when p≤1.
When p>1, an≤1(logn)p. Let cn=1(logn)p. If ∑cn converges then I will win. But now I am stuck. Is ∑cn converges? Then how can I prove it? If not how can I conclude the state of convergence of ∑an for p>1?
Can anybody please help?
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