Favourite links

I am a member of the American Mathematical Society.

An amusing (but informative) AMS site it their Collaboration Distance page.

From it I find that my Andrew Granville number is 3, my Doron Zeilberger number is 3, my Karl Dilcher number is (of course) 1, my Jon Borwein number is 2, my Neil Sloane number is 4, and my Michel Waldschmidt number is also 4.

Going back a long way in time I find that my Gauss number is 6. It's a pity I don't have a path back to Jacobi, since Karl Dilcher and I introduced the notions of Gauss, and then Jacobi primes, in our eight and tenth papers here.

Mathematical sites

The Works of Leonard Euler Online

Chris Caldwell's Prime Number Site

Keith Matthews' Homepage

The Number Theory Web

History of Mathematics web site

On-Line Encyclopaedia of Integer Sequences

Centre for Experimental and Constructive Mathematics


The Journal of Integer Sequences

Abderrahmane Nitaj's abc conjecture Home Page

Noam Elkies' Computational Number Theory Page

Eric W. Weisstein's mathworld


Distributed Search for Fermat Number Divisors

Fermat number factoring status

L-functions and modular forms Data Base

Carlos Rivera's (Prime Puzzles and) Conjectures site

Recent Number Theory submissions at arxiv site

Mathematical Spectrum

Landau's problems

Insights into Mathematics (NJ Wildberger)

Proofs (332, so far) of the Quadratic Reciprocity Law

Personal web sites. Here, in chronological order, the first five - Andrew, Doron, Karl (my wonderful co-author), Jon and Neil - were especially important in my mathematical life, and the sixth - Michel - was a great moral support. Merci beaucoup Michel.

Andrew Granville

Doron Zeilberger

Karl Dilcher

My ten papers (2008-2015) with Karl are here

Jonathan Borwein

N.J.A Sloane

Michel Waldschmidt

François Morain

Franz Lemmermeyer (1)

Franz Lemmermeyer (2)

David Bailey

Herbert Wilf

Katherine E. Strange (a great discovery of 3rd November 2023)

David Eppstein

Bruno Buchberger

Timothy Gowers

Timothy Gowers's Weblog

Donald E. Knuth

Simon Plouffe

Ken Ono

Barry Mazur

Peter Roquette

Terence Tao

Terence Tao's What's New

Frits Beukers

Michael Filaseta

George Shakan's Maths Blog

NJ Wildberger's Maths Blog

Colin Walter

Igor Pak

Colm Mulcahy

Colm's Annals of Irish Mathematics & Mathematicians

Tony O'Farrell's blog

Matt Baker's blog


Contact details. jbcosgrave at gmail.com