David Singmaster
David Breyer Singmaster (born 1939, USA) is a retired professor of mathematics at London South Bank University, England, UK. A self-described metagrobologist, he is most famous for his cube notation to the Rubik's Cube (i.e., what letters denote what face to turn on the Rubik's Cube) and his huge personal collection of mechanical puzzles and books of brain teasers. He is also interested in the history of computers.In combinatorial number theory, Singmaster's conjecture states that there is a finite upper bound on the number of times a number other than 1 can appear in Pascal's triangle. Paul Erdős suspected that the conjecture is true, but thought it would probably be very difficult to prove. The empirical evidence is consistent with the proposition that the smallest upper bound is 8.
