MathDB

3

Part of 2021 Moldova EGMO TST

Problems(1)

Prove that $9$ divides $A_n=16^n+4^n-2$ for every nonnegative integer $n$.

Source: Moldova EGMO TST 2021

2/4/2023
Prove that 99 divides An=16n+4n−2A_n=16^n+4^n-2 for every nonnegative integer nn.
number theory