IMC 1994 · Problem 6

Day 222 points1st IMC · Plovdiv, Bulgaria

Statement

Find

limNln2NNk=2N21lnkln(Nk).\lim_{N \to \infty} \frac{\ln^2 N}{N} \sum_{k=2}^{N-2} \frac{1}{\ln k \cdot \ln(N-k)}.

Note that ln\ln denotes the natural logarithm.

Official solution

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