2021 JMPSC Accuracy Problems/Problem 9
Contents
[hide]Problem
If is a strictly increasing sequence of positive integers that satisfies
find
.
Solution
Say we take as
as an example. The first few terms of the inequality would then be:
But
, reaching a contradiction.
A contradiction will also be reached at some point when or when
, so that must mean
.
~Apple321
Solution 2
We recall the identity that is monotically increasing. Here, we have the same case,
,
, and so on. The answer is
~Geometry285
See also
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