IMO 2005, Number Theory Shortlisted Problem

I go over a number theory problem from the 2005 International Math Olympiad. I discuss the thought process behind my solution to this math competition problem.
Video Notes: umd.box.com/s/0lov00imy19tzlq...
Number Theory Problems: • Number Theory
IMO Problems: • IMO, The International...
Putnam Problems: • Putnam Math Competition
IMC Problems: • IMC, International Mat...
IMO 2023:
P 1: • International Math Oly...
P 2: • International Math Oly...
P 4: • International Math Oly...
P 5: • International Math Oly...
IMO 2022:
P 2: • International Mathemat...
A2: • IMO 2022, A2, Find the...
N2: • IMO 2022, N2, A Neat N...
N3: • IMO 2022, N3, Find the...
N8: • IMO 2022, Shortlisted ...
IMO 2021:
P 1: • International Math Oly...
A1: • International Math Oly...
A2: • International Math Oly...
A3: • International Math Oly...
C1: • International Math Oly...
N3: • IMO 2021, An Interesti...
IMO 2020:
P 2: • International Math Oly...
IMO 2019:
A5: • International Math Oly...
A6: • IMO 2019, Shortlisted ...
N2: • International Math Oly...
IMO 2018:
A1: • IMO 2018, Functional E...
IMO 2005:
P4: • IMO 2005, Problem 4; A...
N4: • IMO 2005, Number Theor...
IMO 1987:
P 4: • IMO 1987, Problem 4; A...
IMO 1977:
• A Challenging IMO Func...
IMO 1961:
P 1: • International Math Oly...
P 3: • IMO 1961, Problem 3, S...

[@Oppenheimer-mr8pk]

Nice work sir! Subscribed!

[@perlovgren919]

I see. clever work. 🙌

[@dakcom-mk6mp]

Nice

[@kikilolo6771]

2:33 why isn't it when n is divisible by 4 ? (Instead of n is divisible by 2)
edit : sorry you say it just after : bc a^2+1 isnt divisible by 4.

[@omarleonidez7200]

Please would you solve the problems of RMM 2024? 😊

[@DrEbrahimian]

Can you send me a link? I will take a look!

[@omarleonidez7200]

Thanks