Questions on Pell's & Non-Linear Diophantine Equations UG Level

[matqkks]

Are there any resources of questions on the topic of Pell's and non linear Diophantine equations? I am looking for interesting results which are required to be solved. This is for a typical second year undergraduate level.
Thanks.

 

[Petek]

Pell's Equation appears to meet your criteria.

 

[Opalg]

Have you looked at https://mathhelpboards.com/showthread.php?2905-The-Pell-Sequence in this forum?