How to create seemingly random arrangement of tiles in a grid?

I am making a game with a huge environment where terrain tiles appear as the player gets close enough to them. It can be thought of as a grid of tiles with coordinates starting at (0, 0), and extending outwards in all directions. I will have a variety of these terrain tiles, and I need them to be placed on the map in a way that appears to not have a pattern, but it can not be random either. Manually setting the tiles is not an option because the map will be gigantic. I need a function that will take the map coordinates and output which tile to spawn. Thanks in advance!