Get out your timer and number two pencil to see if your arithmetic skills are still sharp.

Little progress had been made in solving Ramsey problems since the 1930s. Now, researchers have found the answer to r(4,t), a longstanding Ramsey problem that has perplexed the math world for decades.

A seemingly simple set of rules kicks off a kind of mathematical magic trick, which has kept great minds busy since the 1930s ...