Daniel Larsen and Carmichael numbers

[damefox]

Daniel Larsen is a name that may be familiar to regular solvers of the NYT crossword. His most recent effort is this one, and his debut in 2017 made him the youngest constructor in NYT history. Apparently (and perhaps this is no great surprise), he's also a math prodigy: https://www.quantamagazine.org/teenager ... -20221013/!

[oldjudge]

One more possibility for MIT’s Putnam team. When I was there there were always so many possibilities for the team that they could never select the right trio. One fellow who was a year behind me, Don Coppersmith, was in the top five in the country on the Putnam all four of his years at school.