Solving recurrence relations

 Here are a few good resources:

1. https://www.tutorialspoint.com/discrete_mathematics/discrete_mathematics_recurrence_relation.htm
   
2. http://discrete.openmathbooks.org/dmoi2/sec_recurrence.html
   
3. https://www.geeksforgeeks.org/different-types-recurrence-relations-solutions/
   
4. https://www.geeksforgeeks.org/discrete-mathematics-types-of-recurrence-relations-set-2/?ref=rp
   
5. https://www.geeksforgeeks.org/practice-set-recurrence-relations/?ref=rp
   
6. https://www.geeksforgeeks.org/how-to-solve-time-complexity-recurrence-relations-using-recursion-tree-method/?ref=rp
   
7. https://users.cs.duke.edu/~reif/courses/alglectures/skiena.lectures/lecture3.pdf