In preparation for a talk I am giving to our undergraduate mathematics society, I am trying to collect examples of combinatorial constructions that were found by computer. Thus my question is the following.

**What are the most notable examples of combinatorial constructions found by computer search?**

For example, one fertile area for such results is lower bounds on Ramsey numbers, for example this recent paper by Exoo and Tatarevic. (But since I am looking for constructions, computer-assisted upper bounds on Ramsey numbers don't count.)

Another non-example would be Aubrey de Grey's construction of a unit-distance graph on 1581 vertices with chromatic number 5 (thereby showing that the chromatic number of the plane is at least 5), since the graph was constructed by hand.