Concrete Mathematics, problem 2.29

Evaluating a sum from by partial fraction decomposition, shifting indices of summation, and telescoping. This problem can be found in the great 𝐶𝑜𝑛𝑐𝑟𝑒𝑡𝑒 𝑀𝑎𝑡ℎ𝑒𝑚𝑎𝑡𝑖𝑐𝑠 textbook.

Source: R. L. Graham, D. E. Knuth, O. Patashnik, 𝐶𝑜𝑛𝑐𝑟𝑒𝑡𝑒 𝑀𝑎𝑡ℎ𝑒𝑚𝑎𝑡𝑖𝑐𝑠. 𝐴 𝑓𝑜𝑢𝑛𝑑𝑎𝑡𝑖𝑜𝑛 𝑓𝑜𝑟 𝑐𝑜𝑚𝑝𝑢𝑡𝑒𝑟 𝑠𝑐𝑖𝑒𝑛𝑐𝑒 (2nd ed.), Addison-Wesley Professional, 1994.