Harvey Dubner

Harvey Dubner was an electrical engineer and mathematician who lived in New Jersey, noted for his contributions to finding large prime numbers. In 1984 he and his son Robert developed the Dubner cruncher, a board that used a commercial finite impulse response filter chip to speed up dramatically the multiplication of medium-sized multi-precision numbers, to levels competitive with the supercomputers of the time. He found many large primes of special forms, including repunits, Fibonacci primes, prime Lucas numbers, twin primes, Sophie Germain primes, Belphegor's prime and primes in arithmetic progression, and in 1993 he was responsible for more than half the known primes of more than two thousand digits. He originated Dubner's conjecture, which proposes that all even numbers greater than 4208 are the sum of two primes that have a twin. He lived from 1928 to 2019.