Integers free of prime divisors from an interval I, West Coast Number Theory Conference, Pacific Grove, December 18-21, 1997.
Integers free of prime divisors from an interval II, West Coast Number Theory Conference, San Francisco State University, December 17-20, 1998.
Continuous Geometric Average Rate Options, MAA Sectional Meeting, Southern Utah University, March 25, 2000.
Integers with dense divisors, AMS Sectional Meeting, University of Utah, October 26, 2002.
On the distribution of divisors, Colloquium, Brigham Young University, November 17, 2003.
An equivalence for the Riemann hypothesis in terms of coefficients of orthogonal projections, AMS Sectional Meeting, University of Utah, October 7, 2006.
Zeros of Dirichlet series with periodic coefficients, Zeta Functions, Moscow, December 4, 2008.
Zeros of Dirichlet series with periodic coefficients, Graduate Workshop on Zeta Functions, L-Functions and their Applications, Utah Valley University, June 1, 2009.
The distribution of the divisor function, Seminar, Brigham Young University, January 25, 2010.
The distribution functions of σ(n)/n and n/φ(n), Western Number Theory Conference, Utah Valley University, December 16, 2010.
Repeated values of the sum-of-divisors function, MAA Sectional Meeting, Southern Utah University, April 8, 2011.
On the ratios of consecutive divisors, West Coast Number Theory Conference, Pacific Grove, December 16, 2013.
Egyptian fractions, practical numbers and the distribution of divisors, Colloquium, Brigham Young University, October 28, 2014.
On practical numbers and related topics, AMS Sectional Meeting, University of Alabama, March 28, 2015.
The distribution of divisors and related problems, Seminar, University of Missouri, October 20, 2015.
Polynomial analogues of some results in number theory, West Coast Number Theory Conference, Pacific Grove, December 18, 2015.
A sieve problem and its application, Canadian Number Theory Association XIV, Calgary, June 20, 2016.
When shifted primes are practical, West Coast Number Theory Conference, Pacific Grove, December 17, 2016.
The degree distribution of polynomial divisors over finite fields, Mathematical Congress of the Americas, Montreal, July 26, 2017.
On the constant factor in several asymptotic estimates, West Coast Number Theory Conference, Pacific Grove, December 19, 2017.
The constant factor in the asymptotic for practical numbers, West Coast Number Theory Conference, Pacific Grove, December 17, 2019.
An extension of the Siegel-Walfisz theorem, Virtual Brazilian Number Theory Seminar, February 18, 2021.
An extension of the Siegel-Walfisz theorem, Online Number Theory Seminar, Xi'an Jiaotong University, China, March 18, 2021.
A general sieve problem, Séminaire de Théorie des Nombres de Nancy-Metz, Nancy, France, May 5, 2022.
A general sieve problem, Séminaire Ernest, Marseille, France, May 10, 2022.
A general sieve problem and its analogues in combinatorics, Séminaire équipe ADA, Calais, France, June 9, 2022.
Somewhat smooth numbers in short intervals, Joint Mathematics Meetings, Boston, January 6, 2023.
The Schinzel-Szekeres function, West Coast Number Theory Conference, Henderson, NV, December 16, 2023.
The Schinzel-Szekeres function, Canadian Number Theory Association XVI, Toronto, June 12, 2024.
An extension of smooth numbers: multiple dense divisibility, Integers Conference 2025, Athens, Georgia, May 15, 2025.