THE UPS AND DOWNS OF DANIEL LARSEN
FOR A LONG time, prime numbers kept Daniel Larsen up at night. Prime numbers and their weird cousins, Carmichael numbers, which act like primes but aren’t. Daniel would lie in bed in his split-level house on a quiet street in Bloomington where his parents, math professors at IU, slept in a bedroom nearby, and think about a complex math problem concerning Carmichael numbers. It was a problem that his father, Dr. Michael Larsen, estimated Daniel had little chance of solving as it had stumped a trio of mathematicians, whose cumulative ages at the time of their breakthrough paper on the subject was 136.
Daniel was 17. A prime number. Two less than its twin prime number, 19, but more on that later.
“It seemed like a long shot to me,” recalls Michael Larsen. We’re talking math in the Larsens’ living room, a big, open space with a piano, lots of books, a bowl of seashells, and several menorahs on the fireplace mantle. “It wasn’t an absurdity, not hopeless, but I thought if he was going to work on a problem for a long time and get frustrated, it could be a negative experience. But he was into it. I didn’t tell him not to do it. He probably wouldn’t have listened to me if I had.” This last bit makes Daniel laugh.
“You said I had a 10 percent chance!” he says. Daniel looks a bit like Harry Potter—thin, brown hair, glasses, black socks. He’s soft-spoken and shy, and laughs easily at himself. “That wasn’t really discouraging for me. I wanted to prove you wrong.”
Daniel is really good at things many people struggle with. Things like Rubik’s Cubes, chess, spelling bees, crossword puzzles, and math. When Daniel is interested in something, he takes a deep dive—and often succeeds at the highest level. Take crossword puzzles. Daniel was just 13 when he published a Tuesday crossword puzzle in The New York Times, the youngest constructor in the history of the newspaper. Since then, he has published 10 more. The Times pays $750 a puzzle.
“I think it’s
