Harvey Dubner
Encyclopedia
Harvey Dubner is a semi-retired engineer living in New Jersey
, noted for his contributions to finding large prime number
s. In 1984, he and his son Robert collaborated in developing the 'Dubner cruncher', a board which used a commercial finite impulse response filter chip to speed up dramatically the multiplication of medium-sized multi-precision
numbers, to levels competitive with supercomputers of the time, though nowadays his focus has changed to efficient implementation of FFT-based
algorithms on personal computers.
He has found many large prime numbers of special forms: repunit
s, prime Fibonacci
and Lucas numbers, twin primes, Sophie Germain prime
s, and primes in arithmetic progression
. In 1993 he was responsible for more than half the known primes of more than two thousand digits.
Dubner is also credited with the invention of the first blackjack point count (The High Low Count) which is used by most blackjack card counters today. This was presented at the Fall Joint Computer Conference held in Las Vegas
in 1963 at a panel titled "Using Computers in Games of Chance and Skill".
New Jersey
New Jersey is a state in the Northeastern and Middle Atlantic regions of the United States. , its population was 8,791,894. It is bordered on the north and east by the state of New York, on the southeast and south by the Atlantic Ocean, on the west by Pennsylvania and on the southwest by Delaware...
, noted for his contributions to finding large prime number
Prime number
A prime number is a natural number greater than 1 that has no positive divisors other than 1 and itself. A natural number greater than 1 that is not a prime number is called a composite number. For example 5 is prime, as only 1 and 5 divide it, whereas 6 is composite, since it has the divisors 2...
s. In 1984, he and his son Robert collaborated in developing the 'Dubner cruncher', a board which used a commercial finite impulse response filter chip to speed up dramatically the multiplication of medium-sized multi-precision
Arbitrary-precision arithmetic
In computer science, arbitrary-precision arithmetic indicates that calculations are performed on numbers whose digits of precision are limited only by the available memory of the host system. This contrasts with the faster fixed-precision arithmetic found in most ALU hardware, which typically...
numbers, to levels competitive with supercomputers of the time, though nowadays his focus has changed to efficient implementation of FFT-based
Fast Fourier transform
A fast Fourier transform is an efficient algorithm to compute the discrete Fourier transform and its inverse. "The FFT has been called the most important numerical algorithm of our lifetime ." There are many distinct FFT algorithms involving a wide range of mathematics, from simple...
algorithms on personal computers.
He has found many large prime numbers of special forms: repunit
Repunit
In recreational mathematics, a repunit is a number like 11, 111, or 1111 that contains only the digit 1. The term stands for repeated unit and was coined in 1966 by Albert H. Beiler...
s, prime Fibonacci
Fibonacci
Leonardo Pisano Bigollo also known as Leonardo of Pisa, Leonardo Pisano, Leonardo Bonacci, Leonardo Fibonacci, or, most commonly, simply Fibonacci, was an Italian mathematician, considered by some "the most talented western mathematician of the Middle Ages."Fibonacci is best known to the modern...
and Lucas numbers, twin primes, Sophie Germain prime
Sophie Germain prime
In number theory, a prime number p is a Sophie Germain prime if 2p + 1 is also prime. For example, 23 is a Sophie Germain prime because it is a prime and 2 × 23 + 1 = 47, and 47 is also a prime number...
s, and primes in arithmetic progression
Arithmetic progression
In mathematics, an arithmetic progression or arithmetic sequence is a sequence of numbers such that the difference between the consecutive terms is constant...
. In 1993 he was responsible for more than half the known primes of more than two thousand digits.
Dubner is also credited with the invention of the first blackjack point count (The High Low Count) which is used by most blackjack card counters today. This was presented at the Fall Joint Computer Conference held in Las Vegas
Las Vegas metropolitan area
The Las Vegas Valley is the heart of the Las Vegas-Paradise, NV MSA also known as the Las Vegas–Paradise–Henderson MSA which includes all of Clark County, Nevada, and is a metropolitan area in the southern part of the U.S. state of Nevada. The Valley is defined by the Las Vegas Valley landform, a ...
in 1963 at a panel titled "Using Computers in Games of Chance and Skill".