MathDB

6

Part of 2024 Chile National Olympiad.

Problems(1)

Can you find another prime?

Source:

10/23/2024
Let 133…33 133\ldots 33 be a number with k≥2 k \geq 2 digits, which we assume is prime. Prove that k(k+2) k(k + 2) is a multiple of 24. (For example, 133...33 is a prime number when k=16 k = 16
number theoryChile