A way for contacting Dean Hickerson?
Posted: October 2nd, 2026, 4:15 pm
Subject: Trying to reach Dean Hickerson — an open letter on the 1999 F10 method
Greetings all,
I'm hoping someone here can help me with a matter. I'm trying to reach Dean Hickerson, and I'd like to leave this open letter in case he — or someone who knows him — sees it.
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Dear Professor Hickerson,
You don't know me, though we once shared a mailing list. My name is Joe Crump. In June 1999 I was a member of the moderated number-theory list, and I watched the F10 thread unfold — Klinger's question on the 7th, Richard Guy's history on the 10th, and on the 11th, your post.
I am writing because the historical record never gave your method your name, and I would like to reunite them.
Your post proposed looking for solutions of the form n = rp, with r a small odd number and p a prime not dividing r — the condition 2^n ≡ q (mod n) becoming 2^(rp) ≡ q (mod r), with p | 2^r − q — and you closed with the invitation: "My search used Mathematica's factorization routine. Someone with a better factorization program could probably fill in some more values."
Thirteen days later, Peter Montgomery announced the 65-digit solution, found at CWI by taking n = r·q with r = 485 and factoring 2^485 − 3: your method exactly, attributed only to "guessing." I want to be plain: I allege nothing about anyone's intent. I observe only that the record, as written, never says your name — and the method deserves its author.
Since then the method has had a life. I found two F10 solutions by it myself — 8,365,386,194,032,363 and 10,991,007,971,508,067 (the fourth and fifth terms of the OEIS sequence, below 10^18). This year I built an exact search program implementing your method from the ground up; it has re-derived and verified every known solution, and I keep a permanent record of each one with its provenance. I now run two parallel sweep threads hunting a sixth solution, larger than anything known. One of them is named the Professor Hickerson thread.
Twenty-seven years later, your eleven lines are still the engine of the hunt. I thought you should know that someone noticed — and that the record is being corrected, one triplet at a time.
With admiration and gratitude,
Joe Crump
P.S. Your post, for reference: https://listserv.nodak.edu/cgi-bin/wa.e ... 49.9906&S=
Greetings all,
I'm hoping someone here can help me with a matter. I'm trying to reach Dean Hickerson, and I'd like to leave this open letter in case he — or someone who knows him — sees it.
---
Dear Professor Hickerson,
You don't know me, though we once shared a mailing list. My name is Joe Crump. In June 1999 I was a member of the moderated number-theory list, and I watched the F10 thread unfold — Klinger's question on the 7th, Richard Guy's history on the 10th, and on the 11th, your post.
I am writing because the historical record never gave your method your name, and I would like to reunite them.
Your post proposed looking for solutions of the form n = rp, with r a small odd number and p a prime not dividing r — the condition 2^n ≡ q (mod n) becoming 2^(rp) ≡ q (mod r), with p | 2^r − q — and you closed with the invitation: "My search used Mathematica's factorization routine. Someone with a better factorization program could probably fill in some more values."
Thirteen days later, Peter Montgomery announced the 65-digit solution, found at CWI by taking n = r·q with r = 485 and factoring 2^485 − 3: your method exactly, attributed only to "guessing." I want to be plain: I allege nothing about anyone's intent. I observe only that the record, as written, never says your name — and the method deserves its author.
Since then the method has had a life. I found two F10 solutions by it myself — 8,365,386,194,032,363 and 10,991,007,971,508,067 (the fourth and fifth terms of the OEIS sequence, below 10^18). This year I built an exact search program implementing your method from the ground up; it has re-derived and verified every known solution, and I keep a permanent record of each one with its provenance. I now run two parallel sweep threads hunting a sixth solution, larger than anything known. One of them is named the Professor Hickerson thread.
Twenty-seven years later, your eleven lines are still the engine of the hunt. I thought you should know that someone noticed — and that the record is being corrected, one triplet at a time.
With admiration and gratitude,
Joe Crump
P.S. Your post, for reference: https://listserv.nodak.edu/cgi-bin/wa.e ... 49.9906&S=