2022 Lehmer Prize Awards

We are pleased to announce the winners of the 2022 Dick and Emma Lehmer prizes, given to the organizing committee’s favorite talks of the conference, one to a new speaker at the conference, and another chosen from among all the speakers.

The 2022 recipients of the Lehmer Prize are:

  • Ingrid Vukusic: Consecutive tuples of multiplicatively dependent integers
  • Lee Troupe: An Erdős-Kac Theorem for Sums of Proper Divisors

Congratulations to our award winners, and we hope to see you in 2023!

WCNT 2022 Schedule and Problems Sets Available

The 2022 WCNT Schedule has now been posted. Thanks Amy Wooding for all your hard work putting it together!

And once again, thanks to the tireless efforts of Gerry Myerson. the 2021 Problem Set is also available.

See you online, and at Asilomar!

Announcing WCNT 2022!

We are pleased to invite you to the  2022 edition of the West Coast Number Theory (WCNT) Conference (the 53rd such conference). This year’s event is dedicated to the memory of WCNT’s first attendee: John Brillhart, who passed away on May 21, 2022, at the age of 91.

We will be honoring the memory of John Brillhart in a special session of talks and an in-person banquet. John instilled in us a strong sense of inclusiveness, accessibility, welcoming, and not taking ourselves too seriously in hosting WCNT. We remember John and his influence on us as we continue the tradition of an informal, welcoming, family-style event where we can enjoy eating cookies while sharing our stories, laughs and mathematics together. 

WCNT 2022 will be a hybrid event—with the first half primarily-virtual (Dec 15-17, 2022), and the second primarily-in-person (Dec 18-19, 2022). The primarily-in-person events will take place at the Asilomar Conference Grounds in Pacific Grove, CA. There will be childcare available for the duration of the conference (virtual and in-person) at Asilomar. In short:

West Coast Number Theory 2022: In Memory of John Brillhart

Full Details: http://westcoastnumbertheory.org

This year, WCNT will feature three main kinds of sessions: 

  • Talk sessions: a series of short (15- to 20-minute) talks for presenting current work
  • Problem sessions: sessions focused on real-time collaboration and discussion on problems of interest; and 
  • Community sessions: building on last year’s successful inaugural edition, these are themed sessions where we dig into relevant, but “non-mathematical” problems of interest to number theorists (Last year’s topics included: mental health, finding collaborators, career changes, non-academic career options, and inclusion).


Registration for WCNT 2022 is now open. Early registration ends November 15, 2022, after which registration fees will increase by $25. Limited financial assistance may be available for those who need it.

Full details on registration and accommodations can be found at https://westcoastnumbertheory.org/registration.

Same but Different

We’re at Asilomar, and it’s still West Coast Number Theory, but to keep doing it well, we have to evolve with a rapidly changing landscape. We’ll highlight some of the differences in this year’s event below. Please see the website for complete event details

Event Schedule and Locations

In the spirit of making a space that’s accessible and welcoming to all, this year’s event will be a hybrid event. Some portions will be hosted primarily-virtual, and some primarily-in-person. (This is our first attempt at hybrid at WCNT.) 

“Primarily Virtual”

The primarily-virtual, portion of WCNT 2022 will be held from December 15-17. Talks, problem sessions, and community sessions will be presented live on Zoom, and where possible, recorded for offline (time-shifted) viewing by attendees.

We will also have in-person gathering spaces and ways to engage in-person during the mainly virtual portion of the conference. Please note that having a way to connect online to Zoom will be essential for all participants, including those who are present at Asilomar (if this would be a barrier for you in some way, please let us know and we will help as best as we can).

The first event will be an virtual opening reception hosted on Zoom the night of December 15th, followed by the first business meeting, where we schedule the talks for both the virtual and in-person components.

We will also follow the tradition of only scheduling a half-day on December 17th. 

“Primarily In-Person”

The primarily-in-person portion of WCNT 2022 will be held from Dec 18-19 at the Asilomar Conference Grounds. 

Talks, problem sessions, and community sessions will be presented in-person during these days. We are planning to record the talks from the primarily-in-person portion of the conference and to make them available online for all participants. However, we will not be live-streaming talks (we’ll save that challenge for a future edition of the conference).

There will be an in-person banquet on Dec 18. Tickets for this banquet are $65. (Children 3-12 y.o. are $30, 2 and under are free)

Note on accommodations: Unlike in the past, there is no room block for WCNT at Asilomar. In other words, no rooms are being held for the conference, and no meals will be provided. At this time of year, there is lots of availability in the area, so feel free to stay at the hotel of your choice, and enjoy the great food the area has to offer. (Heck, you could even stay at Asilomar!). A list of nearby hotels is on the location page for the conference.

Celebrating John Brillhart

There will be special sessions during both the online and in-person portions of the conference to celebrate the contributions of John Brillhart. If you would like to give a talk in these sessions, please make a note of that on your registration form. The banquet on the 18th will be held in honour of John (in-person only).

In addition, Tom Struck is donating John’s large collection of math (especially Number Theory) books to the in-person attendees of West Coast Number Theory. In his words:

I very much would like to distribute them for free to any who wanted them;  I think that John would love to have them in the hands (and libraries) of fellow mathematicians who would enjoy them as reference material just as he did.

Thanks to Tom for this incredibly generous gesture!

Introducing: Childcare

West Coast Number Theory has always aimed to be a conference without barriers. This year, we are adding a childcare option for attendees who wish to participate in either the virtual or in-person portions of the event, but have little ones they need to take care of. 

Childcare will be available at Asilomar for the full duration of the event: Dec 15 – Dec 19. (Note: this includes the primarily-virtual portion of event, so attendees can fully participate in WCNT, while knowing that their kids are well taken care of).

There will be a separate fee for childcare. If you are interested in making use of childcare, please indicate this on your registration form, and we will be in contact with further details.


We realize there can be challenges to attending any form of event. If you have circumstances that would make it difficult for you to attend WCNT this year, and you think a small grant could help you to overcome these challenges, please submit a proposal answering the questions “how much” and “how it will help” to: info@westcoastnumbertheory.org.

In Memory of John Brillhart

With a heavy heart, we bring you the news that West Coast Number Theory’s very first participant, John Brillhart, has died this year.

John passed away on May 21, 2022, at the age of 91.

A few years ago, we asked John to describe the origin of the meeting now known as the West Coast Number Theory conference. This is the message he sent in reply:

In January 1967, I got my PhD from Berkeley under D. H. Lehmer and then moved to Tucson, Arizona that fall to start teaching at the University of Arizona. That December at Christmas, I returned to Berkeley to visit my family, so the Lehmers and Robinsons decided to have a Christmas get-together in the form of an informal mini meeting with talks as well.

Dana Scott, Hansraj Gupta, and Don Knuth, who drove up from Stanford, came to the meeting. It was very pleasant. The following Christmas, when I again returned to Berkeley, the party/meeting was repeated; Emma Lehmer and Julia Robinson this time made cookies.

In August of 1969, there was a remarkable meeting at Oxford University on computational number theory to which a huge representation of number theorists came. There is a wonderful photograph of this meeting that is available on the internet. It was at this meeting that the Lehmers decided that they would make the Christmas meeting an annual affair, which they did the following Christmas. And thus, the meeting was founded, and though it has changed over the years, it has remained the same informal, pleasant venue that welcomes mathematicians, young and old, to come and talk about what they want.

John Brillhart is likely best known mathematically for his work on the continued fraction factoring algorithm with Mike Morrison, which is said to have ushered in the modern age of integer factoring methods.

John was also one of the original board members of the Number Theory Foundation, a non-profit organization that supports number theory events.

We will be honoring John Brillhart this year during the West Coast Number Theory conference Dec 15-19, 2022.

2021 Lehmer Prize Awards

We are pleased to announce the winners of the 2021 Emma and Dick Lehmer prizes, given to the organizing committee’s favorite talks of the conference. Since we were having an agonizingly difficult time picking just two excellent talks, and since we didn’t give out any awards during the pandemic pause of 2020, we decided to double the number of recipients this time around.

The 2021 recipients of the Lehmer Prize are:

  • Shanna Dobson: Diamond L-Groups and Diamond Modular Curve
  • Vaishavi Sharma: Arithmetic properties of the divisor function
  • Johann Thiel: Solving the membership problem for certain subgroups of SL_2(Z)
  • Sarah Arpin: Supersingular Elliptic Curve Isogeny Graphs with Level Structure

Congratulations to all our award winners, and we hope to see you in 2022!

50th Anniversary Problem Set posted

Thanks to the tireless work of Gerry Myerson, the notes from the 2019 problem sessions are now available online. Thanks Gerry for all your hard work!

For this problem set, and many more, visit our Problem Sets page.

2019 Lehmer Prizes

We are pleased to announce the winners of the 2019 Emma and Dick Lehmer prizes, given to the committee’s favorite talks of the conference. The 2019 recipients are:

Congratulations to our 2019 recipients!

2018 Lehmer Prizes

We are pleased to announce the winners of the 2018 Emma and Dick Lehmer prizes, given to the committee’s favorite talks of the conference. The 2018 recipients are:

Congratulations to our 2018 recipients!

2017 Lehmer Prizes

We are pleased to announce the winners of the 2017 Emma and Dick Lehmer prizes, given to the committee’s favorite talks of the conference. The 2017 recipients are:

Congratulations to our 2017 recipients!

2016 Lehmer Prizes

We are pleased to announce the winners of the 2016 Emma and Dick Lehmer prizes, given to the committee’s favorite talks of the conference. The 2016 recipients are:

Congratulations to our 2016 recipients!