E.g., I have a vector `[1, 2, 3]`, and I want to update the second element so that the vector becomes `[1, 5, 3]`. In other languages, I would just do something like `array[1] = 5`, but I'm not aware of anything that would allow me to do this easily in Clojure.

Thoughts on how to accomplish this, or on whether I should be using a different data structure?