IMO Shortlist 1995 problem NC1
Dodao/la:
arhiva2. travnja 2012. Let
be a positive integer. Show that there are infinitely many perfect squares of the form
where
is a positive integer.
%V0
Let $k$ be a positive integer. Show that there are infinitely many perfect squares of the form $n \cdot 2^k - 7$ where $n$ is a positive integer.
Izvor: Međunarodna matematička olimpijada, shortlist 1995