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Physical Sciences and Mathematics Commons

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Theory and Algorithms

Selected Works

Andrew Shallue

Articles 1 - 2 of 2

Full-Text Articles in Physical Sciences and Mathematics

Tabulating Pseudoprimes And Tabulating Liars, Andrew Shallue Dec 2015

Tabulating Pseudoprimes And Tabulating Liars, Andrew Shallue

Andrew Shallue

This paper explores the asymptotic complexity of two problems related 
to the Miller-Rabin-Selfridge primality test.  The first problem is to 
tabulate strong pseudoprimes to a single fixed base $a$.  It is now proven 
that tabulating up to $x$ requires $O(x)$ arithmetic operations and $O(x\log{x})$ bits of space.
The second problem is to find all strong liars and witnesses, given a fixed odd composite $n$.
This appears to be unstudied, and a randomized algorithm is presented that requires an 
expected $O((\log{n})^2 + |S(n)|)$ operations (here $S(n)$ is the set of strong liars).
Although interesting in their own right, a notable application …


Constructing Carmichael Numbers Through Improved Subset-Product Algorithms, W.R. Alford, Jon Grantham, Steven Hayman, Andrew Shallue Dec 2013

Constructing Carmichael Numbers Through Improved Subset-Product Algorithms, W.R. Alford, Jon Grantham, Steven Hayman, Andrew Shallue

Andrew Shallue

We have constructed a Carmichael number with 10,333,229,505 prime factors, and have also constructed Carmichael numbers with  prime factors for every  between 3 and 19,565,220. These computations are the product of implementations of two new algorithms for the subset product problem that exploit the non-uniform distribution of primes with the property that  divides a highly composite .